SYSTEMS APPROACH FOR HOUSING PROTOTYPE IMPROVEMENT Case Study: Thailand by PISIT ROJANAVANICH B.Arch.(Hons.), Chulalongkorn University Bangkok, Thailand April 1979 SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF'SCIENCE IN ARCHITECTURE STUDIES at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY June 1983 Pisit Rojanavanich 1983 The Author hereby grants to M.I.T. permission to reproduce and distribute copies of this thesis document in whole or in part. Signature of AuthorDepartment of Architecture May 6, 1983 Certified by Assoc Eric Dluhosch Ph.d. te Professor of Building Technology Thesis Supervisor Accepted by Departmental N. John Habraken, Chairman Committee on Graduate Students MASSACHUSE S INSTITUTE OF TECHNOLOGY MAY'26 1983 LIBRARIES SYSTEMS APPROACH FOR HOUSING PROTOTYPE Case Study: IMPROVEMENT Thailand by PISIT ROJANAVANICH 1983 to the Department of Architecture on May 6, Submitted in partial fulfillment of the requirements for the Degree of Master of Science in Architecture Studies. ABSTRACT low the need for housing, especially for urgent The income families in most developing countries, is found to be of adaptation various factors such as the by exacerbated inappropriate policies, construction standards, zoning laws, the to attention of lack and policies, tenure land development of appropriate housing technology and responsive design method to user requirements. at aims study this above, the of light the In comprehensive guidelines for the improvement of determining such exemplify To Thailand. in prototypes housing typical a housing model is selected, i.e., a guidelines, walk-up apartment of the National Housing Authority. systems a of proposed by means is improvement The building building and the introduction of the to approach the allow The systems concept would concept. performance solver to deal with any set of problems, related to problem between interactions whole, within which a as buildings factors in construction industry interact with each various provides before any resolution is developed. It also other the problem solver to evaluate more rationally the answer he over and enables the process to be repeated developed has of means by situations differing in again over and the is applied Also information. the of transmission intermediary an which would serve as concept performance between user requirements and hardware solution. of guidelines are developed in general five steps The the systems approach to building as follows: 1) statement of data line base and analysis problem 2) objectives, the development of performance criteria, 4) 3) gathering, and of alternative solutions, and 5) evaluation generation selection of alternatives. Accordingly, special attention is on the feedback from the in-use prototypes which is focused proposal in the performance criteria and design reflecting (Step 3&4). Dluhosch Thesis Supervisor: Dr. Eric Title: Associate Professor of Building Technology ACKNOWLEDGEMENTS my regards to this thesis, I wish to express With Prof. Eric deepest appreciation to my thesis supervisor, Dluhosch, for his advice and guidance throughout the work, and particularly for his patience, painstaking reading and corrections along the course of the thesis. Thanks are also due to Prof. Witold Rybczynski, Dr. Vimolsiddhi Horayankura, advices Mr. Thawee Sribunrueng for their professional and for his constructive To Dr. Ranko Bon, and guidances. critism and concern. There are many people in Thailand to whom I am greatly completion of for the help they provided in the indebted to Mr. Direk grateful I am especially thesis. this Thailand Department, of the Building Research Rodsawasdi Mr. Somkid and Technology Research, Science Institute of Ms. Institute and Industrial Standard Saengnil of Thai of the National Housing Authority Somsuk Boonbancha of most of the valuable information Thailand, who provided regarding their agencies. To Anand Withayadamrong, Boonpong Phuvichitsilpa, de Castello Branco, Mark Gross, Moustafa Mourad, Fernando Pornjai Noi, and Preechaya Sittipunt, who have provided helping hands in various stages of the study. And last, but never least, to my mother, for her and solid support during my studies abroad. love TABLE OF CONTENTS --------------- INTRODUCTION.............................. CHAPTER 1: 6 BACKGROUND 1.1 Reasons for the Study................ 1.1.1 Proliferation of High Density Housing........................ 1.1.2 Scale of Housing Demand which cannot be met by Conventional 10 Approach....................... ...............................-. 1.1.3 Inability to fulfill users' requirements................... .... 29 1.2 State of the Art in Building Industry ......32 in Developing Countries.............. 1.3 Analysis of Context Variables........ ...... 35 1.4 Systems Approach to Building......... ..... 40 1.5 Study Methodology.................... ..... 44 PROGRAM & OBJECTIVES 2.1 Program........ ........................ 2.1.1 Background....................... 2.1.2 Basic Data of the Site........... 2.1.3 Planning Criteria................ 2.2 Objectives............................. .46 .46 .49 .52 .56 CHAPTER 3: PROTOTYPE & PROPOSED CONSTRUCTION SYSTEMS 3.1 Description of Selected Prototype...... 3.2 Proposed Systems of Construction....... 3.2.1 Conventional System.............. 3.2.2 Small Component System........... 3.2.3 Prefabricated Post & Beam System. 3.2.4 Prefabricated Panel System....... 3.3 Comparative Cost Analysis.............. 3.3.1 Cost Determination............... 3.3.2 Cost Comparison.................. 57 59 59 63 68 73 78 79 81 CHAPTER 2: CHAPTER 4: DESIGN APPROACH 4.1 Housing for General Criteria Construction Systems Selection...... 4.2 Notes on Existing System............ ...... 85 4.3 Support Detachable Units Approach to Housing............................. ...... 87 91 4.4 Transformed System.................. 4.4.1 Design Proposal............... ...... 4.4.2 Combination of Dwelling Sizes & . . 4.4.4 Infill Elements............... . Tenure Policy....................... . Staging 4.4.3 Support 4.5 CHAPTER 5: Process............... Element Options....... PERFORMANCE & EVALUATION CRITERIA 4 93 .95 .99 102 104 5.1 5.2 5.3 Performance Cnceptp..................... 106 Performance Concept vs Systems Concept.. 109 User requirement & Performance Criteria. 111 5.3.1 Summary of User Feedback... . ....... 111 5.3.2 User Requirements........... . 113 5.3.3 Performance Requirement and Criteria.................... ....... 5.4 Selection Criteria................ ....... CHAPTER 6: 115 123 SYSTEMS EVALUATION & SELECTION 6.1 The Methodology................... 6.1.1 Individual evaluation....... 6.1.2 Group evaluation............ 6.3 Systems Selection and Assessment.. 6.2.1 Alternatives................ 6.2.2 Weighting Criteria.......... 6.2.3 Systems Judgement........... 6.3.4 Systems Assessment.......... 127 127 134 137 138 141 144 148 CONCLUSIONS & RECOMMENDATIONS...........................151 REFERENCES..............................................154 SELECTED BIBLIOGRAPHY...................................157 5 INTRODUCTION is countries levels of minimum meets housing which the shortage of developing facing permanency, hygiene, and habitability. The rapidly in particularly the already crowded urban increasing social with the make the provision concerns areas, coupled these people, expectations of one of the throughout the decent housing of sufficient of countries, developing the of populations expanding urgent problems most chronic the of One countries developing world. the During Thailand are economic in nature. establishment of the National country, progress so far attempt the Despite order to cope with all in 1973, housing task Housing set Housing 2) and completions are far costs are short of Thai through (NHA) the housing problem in seems to suggest that by the National the of Housing Authority appears to be out of hand because of the facts 1) in problems becoming recognized as being both social to face the difficult government housing the decade, past the in the the situation 1) that: the targets Plan. of the families in the shelter, various above levels which most low-income groups can afford. To provide low-income an category opportunity to acquire 6 for etc. self-help housing, core house, namely possibilities, have been investigated and, to a certain extent, implemented by urban the NHA. Regarding urban housing, especially near are prices units), land such as the Bangkok Metropolitan area, where centers, (and so is the demand walk-up apartment type seems to be the apartments, responsive to walk-up changing context the not construction the of are NHA, the by employed currently only the so far. None the less, typical attempted solution dwelling of exorbitant industry and, at the same time, do not adequately respond to real actual or user requirements. examine the potential for improving to going This study is the prototype of walk-up apartments where immediate improvements needed are: adaptability to changing user Greater 1) needs and design and requirements. Development 2) procurement available, tractable which and of methodology a of makes which use of recognizes all resources the need (flexibile and variable) housing for during its life-cycle. 3) Reduction in duration of construction. 4) Higher performance of the unit and facility. The purpose of the study is guidelines special for formulated as "development the improvement of housing prototypes with reference to the walk-up apartment building type." 7 The systems selected of the study is defined as "to utilize scope method, technologies. and user requirements for project with a walk-up apartment as the the a selected building type". The guidelines to be formed are based mainly on: 1) Feed-back from in-use prototypes. 2) The operative factors transformation in the building industry and the various context variables at present. 3) The program, objectives, and resources of the project. The objectives stated for the study are as follows: 1) To compile available information relevant to the prototype, and form a comprehensive analysis of the possibility of improvement, considering a systems approach. 2) To confirm criteria and standards to be in the selected project whether it is satisfied constructed by conventional methods and/or by any other buiding systems. 3) To develop specific methods of evaluation and selection of the method with regard to the criteria selected. B CHAPTER 1: BACKGROUND 1.1 REASONS FOR THE STUDY 1.1.1 of Proliferation to According "Observations from the 181 High Density Housing Types Environments in Developing Countries", Dwelling Urban of Surveys Wang, Chih-Chien of study 1982, apartment became popular at the present "The walk-up future is projected to proliferate in the and stage, stage" 1) The apartments concludes study that the popularity of walk-up is due to the fact that they are able to achieve very high densities with the potential of savings on service housing type does not perform well, low user process, participation and the However, there are many areas in which infrastructure. during i.e., the high initial project under utilized open spaces. With cost, development respect to developing countries, where the problems of housing shortage are evergrowing, the study refers to walk-up apartments (despite its drawbacks) that, is type walk-up to note that the important is "It the in type dwelling predominant most the to be likely future" 1) 9 of Housing Demand which cannot be met Scale 1.1.2 by Convention Methods of Construction a. Bangkok Demand for Public Housing in the Pressing Metropolis shortage housing are Bangkok so far, there in the on is no comprehensive data there Although some clues which the problem, i.e., squatter housing. The magnitude of the squatter are group category in 1980 low-income other low-income that housing % 9 of the the This population as such types, boat houses, and tenements. only of (see Fig.1.1). not include the number of does housing, private to be 1,050,000 or 60 4 estimated was figure to illustrate in Bangkok, both on government and population land, helpful so-called It is in workers' noteworthy group low-income category can get access to institutional housing by the NHA. Thus, squatter 'substandard' and can housing is considered be taken as a measure of as the housing shortage to a certain extent. Assuming that the low-income population of the Bangkok Metropolis will grow at a rate of 5 % per annum, which is approximately the same rate as the metropolis as a whole, the figure could reach 1,700,000 in ten years. 10 Figure 1.1: Low-Income Housing Types. Source: 7 RURAL HOUSING (SURROUNDING URBAN Kiatfuengfoo, V., MIT Thesis, 1982, p.12. Total low-income residents: 1,766,000*(3) (1) 1980 figures (2) 1978 figures, all other 1976 (3) Modified from Angel As and Wang Shieh-Yu (1978-79) regards the income level, demand the (1975-76) may housing as well be comprehended as almost half population group, unsatisfied in Bangkok being in the of low-income with the percentage constantly increasing. The minimum wage established by the Thai government in 1979 was set World at US$ 810 per year while, according Bank, equivalent National as of US$ absolute poverty the was the year. The line 822 per household, per Housing Authority classified the income groups follows: Fig.1.2); the to below US$ 900 as very low income between US$ 900-1800 as low income; 11 (see between 1800-3000 US$ It is estimated that that considered as high income. . Bangkok of the total of % 10 absolute the below residents who are was line, this, at the same time, constitues about poverty 54 rest the and income; middle as country. Moreover, absolute poverty line, accounts for 33 7. above the of be considered as being in the may the Bangkok population Therefore, 43 7 of the total residents. Bangkok low-income group, the in population urban poverty in low-income category by the NHA standard. Income Levels Figure 1.2: 10000 very high 8000high 5000 400 3000 -- 3500-middle mm --2000 - i1000io - - 5000 80 82- very low 0 50% 1979 40 Sources; 30 20 10 0 USS/household/ye." The NIIA The World Bank Thai Government: Minimum Wage 450 per day 13505 per day 162005 per day The world Bank: The absolute poverty line Due to (US$ 2.25) (US$ 67.5 ) (US$810.0 ) USS land 822/year/household scarcity 12 and the high costs for water, only suffering is not Metropolis housing, but -moreover- cannot for there are institutions which could provide of has and squatter housing for a Problems facing the Production of of Production limited new words, other more visible, to approach low-cost Low-Cost Housing housing in Thailand, by existing scarce resources, can hardly production inefficiency contractors), facing meet increased follows: the of the Government's Housing Policy, the NHA and be can inconsistency The problems demand. pressing housing of in low-income housing solutions. providing the need urgent an indicating terms and more becomes situation of In conditions. physical sanitary savings. proportion extremely low standards of is considerable a where and low income levels almost half the population of Bangkok, a housing b. long term loans with the aforementioned developed financial aside from encouraging facilities, Incorporated of decent management. and housing no Furthermore, mortgage lack provide minimum services, planning, proper sites, new from a as Bangkok the networks, road and electricity, such infrastructure, the necessary urban providing of the outlined roughly as building technical problems teams in projects, and the constraints on inputs. 13 (the implementing construction First of all, the government's housing policy may be considered as basically inconsistent so far. This is mainly by the frequent changes of government in caused past NHA witnessed successively. units, which Finally, the target them of each was raised by units target initial three cabinets and the 170,000 of plan the 1975-1977, decade. For instance, during the reached was not at all realistic, since 270,000 was it clearly beyond the capacity of the NHA and the building industry. kind of This personnel finance, of number entirely programs postponed. management, result, etc. As a delayed of construction were Nonetheless, causing acquistion, such as uncoordinated land problems many was wishful thinking this is a power: be realized by any government in should i.e., the need for long term planning which will but or problem which into a take account not only the effective demand of housing, also the capacity of the industry, coordinated by the NHA, which seems to be the best solution that could be contemplated under given conditions so far. The building i.e., teams is the inefficiency problem second which consist mainly of of the parties, two the NHA and contractors. According to the NHA housing policy 14 in Policy Document No.2, Chapter 5, Housing Authority will be the sole National "The agency responsible for the provision of housing for the low income and medium income families" the careful Despite and poor management. The NHA is, in fact, structure public a enterprise which is more flexible than a public an of previous government agencies, such as Division Housing of Department Office management is is fact The concerned. amalgamation far as organization and as administration of organizational inefficient an with faced still the its operations its organization in the very beginning, the NHA is and are preplanning of that the NHA Clearance Public Welfare, and the Slum of the Bangkok Municipality. Accordingly, its aforementioned problems of been have personnel agencieF. the of and the Housing Bureau most from transferred the The situation exemplifies the management resulting from the process of recruitment. public "Many problems of personnel management in in way to have arisen from the seem enterprises the managers are recruited and the nature of which service conditions under which they operate." 2) Now building the let the second party of the team, the contractors, which are operating in private Entering consider us the entrepreneur realm the of construction in Thailand 15 industry. construction industry is quite as easy, a private since the contractors of inexperienced building of prices resulted in a also competition, for To with cope minimum standard for has entry of As a high such result of unreasonably job. getting the materials and unskilled the situation, bid, often who, most concerned, set a the contractors who win a of the time, are not as well problem, as far as housing contractors qualified. This production is which needs to be solved by the NHA. Regarding difficulties there are a the NHA has sub-contract their work to other another labor. contractors to be eligible for the bidding. However, some of i.e., inept by very competitive market for bidding the sole purpose of by using substandard is rising they try to hold costs down during construction Later, NHA number of 1976 due to the many firms bid on projects at prices, low in materials, exacerbated projects. construction organized which many are from the above, ease Aside management. on of business out went firms and small of time. As a result, a to take one project at a capital. liquid to fixed great number a are there Therefore, ratio of high comparatively a with small, is capital initial required the next problem, the technical in properly implementing housing projects, number of areas which need project planning, 16 to be developed, project tendering, contracting and procurement, and project construction. lack the is housing public implementing of the most critical problems of One information of and project planning. Despite the biggest pool inefficient of professionals working for the NHA, there is still an absence of effective co-ordination and adequate control design, during mechanisms inexperience in process, coupled with low-cost housing which inability are results and produce to the results eventually efficient construction and bidding end of in an products. cost overruns of projects, poor decision-making, area a costly design stage, The planning and the absence of any feed back or evaluation system, etc. far as contracting and bidding are As the concerned, conditions for allowing any contractor to bid on a are past experience project excessed amount reliable qualified legal (only a single contract of one million baht or and contractors, financial once US$50,000), status. they manage to and However, get the try to sub-contract it to another contractor who work, may be unqualified but willing to assume a share of the business. general Substandard performance of buildings is the result. At the same time, this also limits new construction firms, which may provide high performance, but lack the minimum qualifications set by the NHA, to 17 the NHA) contractors operate in way of they want, i.e., as well as, systems during to implement control all activities of controlling over the lacking experience causing problems, specifications result, a on repetitive house building, are since the only the issued by control products of labor, the building. materials, control are poorly managed. necessary and the contractor Accordingly, this causes most of the projects, since scheduling of be the NHA utilization of delays will less, on site, or more sub-contractors. the contractors, The depend on ad hoc decisions of machinery the co-ordinating and country. materials and end of quality has the NHA construction stage, the task important and bidding without any standard bill construction period. During As the bidding process the quantity. Thus, it is difficult to set any standard price, the (with leaving the registered pool, into the work enter and To cope with this issue, it work of constraints on to co-ordinate fully the program, design, and construction. Last but construction labor, and not least, inputs, i.e., the land acquisition, building materials, are also some more serious problems facing housing. 18 the production of finance, of the low-cost especially in Bangkok and other big cities, Land, is but available, developed be could which within land agencies, owned by some government available Bangkok situation. the are still some pieces of there However, housing public for Land price. high exacerbating further is speculation very a at development. is the key word to public housing, but it Subsidy is not always the case as experienced by the NHA. The from the NHA to used in government that However, get heavy financial the support very beginning of its formation. support lasted for only 2 years, i.e., 1976 to 1977. As of today, the NHA is supposed to from with its own resources as much as possible. It operate is inevitable that most of the current housing projects to be designed to suit available scarce financial have resources. Thailand has been experiencing a high mobility of workers -skilled, semi-skilled, and unskilled- the like of which she has never experienced before. existing were heading 1982 left the country, among them, alone, 108,519 workers 3) 88,271 In for Saudi Arabia Thai workers' community of in the Arabian Gulf region. 19 to join the 170,000 persons 4) This phemomenon has created a and has tended to drive up hourly wages it Moreover, country. the of skilled-labor shortage in problem will which construction sector. This problem should be leave to cause many workers expectations seriously considered by responsible government agencies. are steel reinforcing currently and cement materials, building Concerning 'key' construction materials. Wood, which was once very popular, is losing its popularility However, key materials and other related materials for concrete far, such are aggregates, as causing price increases. Unfortunately, there are, accelerated no alternatives of new inexpensive and/or and components so far. Moreover, there is no materials building long-term support for government substantial c. aforementioned the evergrowing demand of the construction, so price. due to its scarcity and high solid any research program at the and present, Housing Supply Despite the establishment of the National Housing still in 1973, the supply of public housing Authority is unable to meet the growing demand. Starting from the first national housing plan to the recent one, the NHA, with faced various housing problems of production, failed to meet the targets it aspired to. In the first years two 20 of the NHA, it was housing the following National Economic and Social at same the the targets set out in Third Development Plan and while time trying to set its own The course. first guidelines for its housing program were set up in the Third National provide to planned NHA, The (1972-1976). Economic and Social Development Plan uncertainties political units 17,000 the Facing 1974-1983. these following change between of per guidelines, from annum government and the NHA 1973-1975, carried on its task based on the 1974-1983 plan. During the housing projects inherited from the complete and two years, the NHA was able to proceed first such agencies, as community housing and previous government housing complexes. Moreover, to formulate urban public development embarked on and also slum improvement plans, the NHA socio-economic conducting surveys in various community. During 1972-1976, the NHA, with limited resources and the attempt to quantify housing need, did not reach the assigned target. Out of 85,000 units of the National Third Development Plan, 31,342 units of housing had in relation to the land available been programmed that time. By 1976, only 12,275 units were at completed. Therefore, the housing construction programs undertaken by the Fig.1.3). NHA were 72,725 units below the During this period, 21 target (see instead of looking at the constraints far fallen on the production of housing, which had 17,000 units per short of the target of year, the NHA was trying to establish the housing needs in the Bangkok Metropolitan area. THIRD PLAN TARGET 69,000-Vl) 0 : 51,000 0 34000-- PROGRAMED 31,342 Units 1 I-q S17,000-- -' 00ACHIEVED 12,275 Units 72 Figure 75 76 Manoharn, S. , "Improving the Production Process of the Housing Industry in Thailand", Report, Bartlett School of Architecture and Planning, London, G.B., 1978, p.8. The that 74 The target of the Third Plan and Achieved by the NHA. 1.3: Source: 73 surveys done in 1975 indicated at that some 110,000 families of all capital were time income groups in the suffering from a housing shortage, and that 85% of these families' income was less than 5,000 baht (US$250) a month. Besides, the surveys estimated that if the housing need increased by 10% annually, the shortage would be 161,051 units by 1980 22 (see Table 1.1) Housing Shortage 1976-1980 Table 1.1: 110,000 121,000 133,100 146,410 161,051 Shortage ------------------------------------------------------------- Housing Source: 1980 1979 1978 1977 1976 making Without Fourth the Under Plan Development the housing shortage. eliminate to order in in per would raise the target to 20,000 units 1975 that it year Parliament pledged to then the government industry, construction the of limitations and potentials the to reference causal any 1975', Report 'Annual Housing Authority, p.24. National Bangkok, Interior the Ministry of (1977-1981), Social and Economic National through NHA was assigned to implement the government's housing policy satisfy the demand of baht the and from Aside sector. National Plan initiated leaving a of country. the to the rest fo provision The NHA planned to planned province to 120,000 units, province each year. 23 The focus than 5,000 build of estimated 160,000 units basic which included the building of housing units the would own target aforementioned, the which time. The NHA set its a month. years, five plan incomes less 120,000 units from completing a years' five within plan was people with (US$250) within to formulate private the the Fourth services, throughout 5,000 units, rotating supply out from In program order within to housing gigantic implement such a the five years, the NHA divided plan according to income groups as follows. Housing Distribution to Income Groups Table 1.2: Household income in Baht/month TargetGroup Type Percent. Distribution Less than 1,500 A 35 1,500-3,000 B 40 3,000-5,000 C 10 5,000+ D 15 Source: A. B. C. D. National Housing Authority, "Annual Report 1975", group income of p.24.(The pattern Bangkok, survey socio-economic on based is distribution the Bangkok for 1972 in AID by conducted Metropolis) was 5,000 units for those whose monthly income for than 1,500 baht (US$75), which accounted less 35% of those who were seeking housing. was imcome units for those whose monthly 5,600 which (US$70-150), baht 1,500-3,000 between accounted for 407 was income units for those whose monthly 1,400 which 150-250), (US$ baht 3,000-5,000 between accounted for 10% Those whose monthly income was more than 5,000 baht seek would 15% for accounted which (US$250), NHA under sector private the from housing to estimated private sector was The assistance. the a third of the work done by about accomplish supplied NHA with some 10,000 housing units being by the private sector annually. The five-year plan 24 (1977-1981) of housing was construction a Accordingly, areas. suburban launched in both urban and was towns study of satellite initiated, responding to the government's town planning policies which were advocating the establishment of new self-contained communities. addition, the NHA made efforts to implement In slum improvement scheme which was considered five-year as more economical a a deal and faster method to with and inadquate housing. The scheme aimed at substandard upgrading 200 slums in the Metropolis. end the At of fiscal year just one new construction could implement i.e., Tung World Bank. The remaining ten projects were it project, Song Hong Project which was funded by the dedicated slum upgrading. Only 2,989 units had been completed to in was NHA It was found that, the plans and policies. revising the 1977, 1978 along with 4,656 units being upgraded. 1979-1981, During target own (US$75m.). The target consisted of 5,596 baht rental core upgrading. only its 1,500 of service NHA had planned according to the available budget, i.e., million units the 7,856 apartments, 19,160 units of site houses, According units and 26,000 units of to the assessment in June altogether 25 of every scheme and slum 1980, were completed. current The five-year plan been (1982-1986) has geared towards distribution of housing construction and into different regions of the country. This investment Notwithstanding Metropolis. own also included in delivery process, achieving its from reach Bangkok the NHA set its and Bangkok program. problems many the housing production which have prevented the targets, as set by the agency government. Will the NHA manage The the new housing targets assigned to it? shown amount of housing supply in each year is Fig.1.4, National of in question then, to be asked is: actual in and external internal both this the NHA has faced conclusion, In to as 7,500 units in the provinces. 30,00 units of slum upgrading is The the above, of completing 42,500 units in target only and dwellers to the the migration of rural reduce living the the people in the provinces, as well of standards to improve expected is decentralization compared Plan. low-cost consistently with the targets set in the It is quite obvious that the production housing fallen quantitative in terms far short of the targets, set the NHA. 26 has by UNITS OF HOUSING X1,000 25 20. 15. 10- 5 O 73 1949 Figure 1.4: 75 77 79 81 Housing supply from 1949-1980 compared with the target of the Third National Economic and Social Development Plan 1972-1976, and the target of the Fourth National Economic and Social Development Plan 977-1981. The actual amount of housing supply in each year: 500 units per annum 1949-1972 965 units 1973 1,456 units 1974 4,921 units 1975 4,933 units 1976 10,013 units 1977 2,989 units 1978 7,856 units 1979-1980 Source: National Housing Authority, 27 "Annual Report YEAR 1975" and "Annual Report 1976". National Housing Authority, "NHA Housing Development Plan 1981-1985 (draft)",, July 1981. 28 1.1.3 Inabilities to fulfill Users' Requirements Housing demand does not exist just in quantitive terms, but is also qualitative as Grant Wanzel writes: dimensional; three for building is demand ".....the Furthermore, qualitative, quantitative, and economic. a there that a crisis would exist were suggested it The demands. these or all of any meet to failure of may be easily examined in terms situation housing 5) these criteria." difficult by as mentioned earlier, is not to perceive. In contrast, qualitative demand is, quantified and However, housing programs which do not quantitative demand, The stated. explicitly take difficult nature, very its to be such demand into consideration are doomed to fail. Housing Pruitt-Igoe country -the USA. As a result, were buildings conditions tolerate this Project in St. Louis exemplifies or less, even in the context of more fact, a "developed" in July 1972, three blown up by dynamite by the central government prevailing in the project any more satisfying qualitative demand is often as not deteriorated to a point, where people could conditions The *. the This problem of case in low-cost housing, and caused more often than not by limited budgets, which translate into poor built environment. a number of that the project was the winner of * Note awards and was published widely as an example architectural of "excellence" in public housing design. 29 as it is undeniable that both economizing, short, In as poor design assumptions about poor people's housing well need led to this sort of disaster. As long as a new approach is and realized, such a mistake will be repeated over not over again, regardless of the context. The fact is, for both developing or developed countries, it is not always the case that economizing is the same as squeezing people in a box. be a better, if not the best, way to deal with must There this difficulty. a result of a survey done in As living concerning the complaints, specific were 1971 by the NHA, there performance of units of walk-up apartments by the NHA. The dwellers not satisfied with ventilation, space requirements and were (see configurat-ion needs, their suit beauty etc. salons apartment messages i.e., activities; commercial Summary of not was it to find users try to convert part of the unit to uncommon 5.3.1 finished in 1978, was Project Housing in Chapter 5, Moreover, after the first phase of the Klong User Feedback). Toey detail units were change space as groceries, such Some too for of the dwellers small various making, dress felt small. These are that the of the some from the users that have to be taken into account for any future projects to be implemented by the NHA. Given for methods the preceding discussions, the situation of incorporating such messages or 30 calls qualitative the built housing environment into aspects of the housing process. The traditional specification total approach, usually employed in low-income housing, is becoming outmoded in of fulfilling user requirements (as reflected terms user using simply user studies discussed above). feedback Thus, instead in of "prescriptive" minimum standards, where varying requirements cannot be easily using "qualitative" criteria possibility of performance should be initiated in a accomodated, for housing new building design and construction. The performance concept, allowing a performance requirement to be stated qualitatively, without prescribing a solution, is such a possibility. specific once properly requirements this applied, would help The mediating and construction hardware solutions. concept, real user However, does not mean that all prescriptive standards would be eliminated, but only those which prevent positive change or innovation. 31 1.2 IN BUILDING INDUSTRY IN DEVELOPING STATE OF THE ART COUNTRIES 6) the Regarding present state of the art of systems in can be countries, developing the following observations made: 1) Most of the dwellings and buildings being erected today are using some open components, manufactured on site or off factories. in site cost reductions compared to conventional 2) No substantial building have been derived so far from systems system in most cases. 3) probably advances in buiding technology are Technical 10 years ahead of the building industry and technology is capable producing almost anything of the market demands in the consumer goods sector. 4) Out of the large number of systems sponsors, only a few appear to be successful. the The key to success seems to be linked to superior organizational management and marketing capabilities of the company. 5) For the high-rise building sector, systems building is more capable building high of playing an important role during the process. This is so because of the relatively overall construction the budgets, repetitive nature of high-rise construction, and the concentration and density construction of construction sites which 32 sites helps for high-rise facilitating the concentration of mechanization and control. 6) It cost comparison is difficult to make a reliable real between each appears to cost its in factors different include company each since systems building analysis. 7) A developing few building systems have originated in countries. However, the superiority of systems building been recently has various realized by governments, and contractors. Consequently, some building builders, have been used with success in low-cost housing system systems in projects such as various prefabricated panel Cuba. 8) calls continuous program of industrial overall part of an as activity building and extensive an for countries developing situation in most housing The development plan, or policy, to bring living conditions to a minimum acceptable standard. Such a program, if factor in may undertaken, the adoption of systems building as part of advocating industrial an an overall 9) Almost, in all abundant to do become a highly important development strategy. developing countries, unskilled labor is and relatively cheap, however, it has nothing with construction the continuous rise in wages workers which may of eventually conventional construction skilled place methods a (which premium on require skilled workmanship and hardly make any use of abundant unskilled labor). 33 Also, unskilled rural migrant labor aspires to higher industrial 10) "status" as labor. The price of conventional building materials to permanent increase. Moreover, these materials continue are being rapidly depleted such as wood. There is need for useful research on newer and cheaper from industrial and agricultural fibre, which e.g.), could materials. 34 materials, waste especially (rice husk, coir replace conventional 1.3 ANALYSIS OF CONTEXT VARIABLES The features main context of variables in Thai construction industry can be outlined succinctly as follows: Labor 7) -Abundance of unskilled and illiterate labor. -Lack of skilled workers. -Labor supply is seasonal. -Carpenters can be easily obtained. -Masons are available. Building Materials and Products 8) -Concrete of is avialable, but suffers the problem seasonal short supply. -Reinforcing steel bars are abundantly available. -Wood is expensive and scarce. -Ready mixed concrete is available. -Some components are gaining more open acceptance such as floor components and concrete block. Land 9) -Land in the city is scarce and extremely expensive especially in the private market. -It land is still for possible to negotiate to utilize housing purposes from other idle government agencies. Transformation Factors in Construction -The Industry 10) majority of builders have had experience 35 with reinforced concrete structures. than -More of half the contracting firms have & beam occasionally employed systems building. system builders employ post the of -Most systems. majority of system builders have experience in -The casting components either on site or in the plant. new generation of systems-concious technicians is -A available. readily mechanization is a common weight -Medium practice most builders. for -Modular has been introduced coordination in the industry, although it is not yet common practice. research program on building systems -No substantial is discernible. -Long term planning of housing is inconsistent and stop-go. -Capital in investment plant equipment and is comparatively low. -Excessive concentration of authority in management. -Workers tend to efficiency-oriented lack proper with new processes, and unfamiliar be productivity incentives to increase productivity (and skill). Transportation 11) -Road transportation is most economical radius of 200 km. 36 within a large building components trailers for -Low-bed or elements are available. Finance 12) NHA -The own its with operate to expected is financial resources as much as possible. The an exemplify above facts obvious characteristic of developing countries, i.e., an of abundance practically, technology, of level the employment, while there is seeking labor illiterate unskilled and dichotomy, and potentially relatively high. The fact is that, due is to minimum wage policy of the government, labor has become the increasingly construction, costly there has been inputs other to relative a raise to tendency in productivity by replacing labor with equipment and by using labor-saving materials and prefabricated components systems. countries Whether or not this is appropriate for and/or developing is highly debatable, especially if one takes into severe shortages of available investment account their capital, labor surpluses, and lack of competent management. However, ought in in order to avoid any preconception of what to be done, we may look at the context variables only terms of whether they are favorable or not to systems development as such. The context variables which 37 can be defined as highly relatively building of All transportation. materials and products, land, and are them systems any for candidates potential are: development to systems favorable building development. The systems variables are building investment. which Since obviously are finance housing of problem unfavorable and without operate the NHA is expected to to government subsidy, it will have to generate its own sources of from financing substantial systems amount savings, of etc. fees, as money required There in is no developing systems building in the very beginning of building development. Regarding labor and other transformation factors, these are for and partially against the initiation partially systems seasonal building. Thus while the lack of skilled labor supply of labor are in favor of systems of and building, the abundance of unskilled labor certainly is not. Likewise, most of transformation factors in the to substantial research shortage for industry systems development while others, e.g., preferrable inconsistent the long program on building term housing development plans, investment plant in and are no systems, capital equipment, and personnel's attitudes towards management, are denying such a development. 38 Whatever are systems constitue 5,5.4) selection concerned, a variable set often of building the case may be, insofar as several with the all of of multiple criteria, unequal values of 39 for the system. The would provide a with these diverse issues. issues (see Chapter importance appropriate best and most methodology outlined in Chapter 6 approach to deal aforementioned the systematic 1.4 SYSTEMS APPROACH TO BUILDING Systems The Approach is a which methodology with the total process of building, its concerned management, and resources. Total context, every process here means from the identification of the need or demand to stage is the completion of the building and its effective life use. Systems Approach has two main features: The stated in performance rather than the clearly are prescriptive and it emphasizes explicitly the inter-relationships terms, of sub-systems within the overall The the goals system. diagram (see Fig.1.5) is an attempt to illustrate major aspects and stages that typify the total building system as a process. At the outset, the Systems Approach is conceived in the of an assumed "market place" of supply and context This users have market comprises, on the one hand, the demand. consumers or of the future buildings, whose needs and requirements to be identified and the resources available to them, on the other. 40 meet MANUFACTURE Figure 1.5: Building System Process Source: Bui l ding System OPERAT./MAINTI Inc. , "The -Development -=. ASSEMBLY System for Potential EVALUATION p. Building," 7 . To bring both parts into a satisfactory balance entails that each is expressed in measurable terms. Measurement is a consideration vital of of needs people, their activities, control of requires an and the equipment use, the spatial configuration necessary to accomodate they and these, Most prediction the Identification implementation. understanding in of the environmental these can conditions to be expressed in be measurable satisfied. terms of quantity and quality. 13) This information can then be translated to describe the range of performances required of the built environment. The descriptions should state how the solution must perform, not what it must be. 41 The resources available to meet specified needs include machinery, materials, finances, skills, manpower plant, land, organization methodologies, administration, and perceived needs and to enter the is the management. resources, available then possible is analysis and ultimately synthesis. This of stages it both for assembled data With modelling phase, using the techniques such as cost analysis, calculations, structural and, perhaps, even mathematical models to simulate the performance of alternative solutions before evaluation range one solution or solution is and alternative possibilities are explored Thus selected. and generated. assessment the of of the evaluation criteria, followed guidance this an under the intended results will be selected implementation of accurate alternative which is considered the most The the by parts stage. This is the manufacture of the buildings and their assembly at the site. The result at stage is not necessarily a building system, it can be acceptable process to be implemented, or even the design buildings of a new financing, or planning, etc. institutional structure, e.g., Thereafter, a range of building systems to be tested or are occupied, used, and/or tested, and subsequently can be evaluated against the goals, 42 objectives, and predictions of the conceptual 43 models. 1.5 STUDY METHODOLOGY necessary and to make full order In use of Systems Approach, it is to establish the steps of operations in the study implementation process. As far as the NHA is concerned, the following steps are suggested: -After the decision for the study has been made, the Department (Research & Planning Department) will send requests to several bureaus to appoint a representative to serve as members of a "project team". -The purpose of the team approach is to assemble a group of experts to work closely with each other and provide material concerning the activities and responsibilities of the various offices. -In order to resolve a given program, these steps are to be undertaken: 1) Identifying statement of objectives 2) Problem analysis and base line data gathering a) State of the art in construction b) All parts of the problem and the relationship between the parts c) The variables and constraints which will affect attainment of the objectives d) Identification of the needs of the potential users of the building through surveys, interviews etc. 3) Development of performance criteria based on user need 4) Translation of performance criteria to performance standards and requirements (technical) 5) Generation of alternative solutions 6) Evaluation and selection of alternatives based on previously defined performance criteria 7) Implementation 8) Evaluation of the actual performance of the selected alternative against the performance criteria 44 N.B. Step 6,7 are beyond the scope of this pager. -After the team is formed, a series of meetings will be held to introduce the project and discuss various methods of system building. -The team then proceeds to discuss advantages and disadvantages of present design and construction methods in order to establish objectives for use facilities. -A group of experts, preferrably the ones who are experienced in performance criteria formulation, will be selected from the team members and then assigned to develop the performance criteria and also the criteria for the selection of the system. -A series of alternatives is developed for: a) Planning aspects b) Hardware solutions: c) Time schedules for construction d) Mechanization, work process, and building design construction and materials relationship e) Relationships with industry -The evaluation and selection of alternatives will eventually take place by means of evaluation procedures by the individual and group. 45 CHAPTER 2: PROGRAM & OBJECTIVES 2.1 PROGRAM 2.1.1 Background In mid 1) 1950's, a community of squatters settled on Port Authority land. Today the settlement constitues a small city the within families giving the total through 6,000 Bangkok Metropolis. The community houses population of 30,374. It has grown from any has considered the three alternatives to the accretive development, independent government intervention. The problems NHA caused by this settlement, since the physical condition is considered as sub-standard and hard to upgrade: 1) Relocation: area Relocation of the families to another on the periphery of the city similar to other government housing projects. 2) Rehabilitation: Rehabilitation of the existing area by improving land utilization, infrastructure, environmental conditions, and community facilities. 3) Return: Return the residents to the rural villages. The government would provide land for new self-help settlements. The determination of desirable possiblity is based on the size of the population, the proximity to employment, and other social benefits. 46 Figure 2.1: CHAOPHRAYA RIVER 0 I? Locality Plan of Klong Toey Slum which solution turns out to be rehabilitation, is to be implemented providing 7,500-8,000 units of walk-up apartments. through The the conclusion has been reached, the After phase first considered, more project or less, was finished as a in model 1978 for and was further development. The solution aim of this study is to to the problem of design determine tentative and construction of prototype by means of the systems approach. 48 a the 2.1.2 Basic Data of the Site 1) Location: city Bangkok approximately is site The center. income residential 10 km. south-east It is located between and an industrial a of the middle/high area near the Chaopraya river. Area: 207 Ha. area Total Port Authority of Thailand occupies 104 Ha. 64 Ha. Squatter community occupies Available area for project development 103 Ha. Boundaries: To the north -Gloy Num Tai residential area -Gloy Num Tai residential area To the east To the south -The Port of Thailand and Chaopraya river To the west -Klong Toey commercial - residential area Ownership: The which for rapid from Port Authority of Thailand acquired the land on the squatter community is located before World War II international shipping facility development. The Port's growth different and the location has attracted many families parts of Thailand to build their houses Port Authority land. 49 on Existing Community: small within Bangkok Metropolis. The community houses 6,000 up adding families of high concentrations of social, symbol independent a is support. It has been and still government any The 30,374. to a total population of through accretive development, grew community from established squatters on Port Authority land, and now constitutes a itself city community of a mid-1950's In health, education, and housing problems. In 1970 the World Bank approved a loan of US$12.5 million for the expansion of docking facilities, of occupation a 20 to public attention the brought has which portion of Port Authority long year the by land squatters of Klong Toey. Zoning: is It residential proposed community. that the site be Port The will reduce a into developed all heavy loading to the new port located near the Gulf of Thailand. Approaches/Access:' The is located road which site approach to the site is through Rama IV road which is about 500 meters north of the site. Arinarong the major street connecting the site with Rama leads to the city center. The traffic volume to is limited. Public buses and private mini-buses the area along Arinarong road. 50 IV the serve Topography/Natural Features: The site is flat. Most of the land in the site is marsh only the edge of the site along Arjnarong road is dry land, land. Soil Condition: surface is composed of The clay with varying depth has bearing capacity. The blue clay limited blue organic fragments and from the surface of around 20-25 m. This a is the most common type of soil condition in Bangkok. Flooding: marsh The in is the site of prone frequent to has trapped the settlement is illegal, there are no utility Construction flooding. water area in the adjacent area the site. Infrastructure/ Community Facilities: Since services are beyond Arinarong road. Health and welfare services available organizations. Arjnarong road. on the All commercial Small through site different social activities are located along are found corner throughout the community. 51 shops/artison 2.1.3 Planning Criteria Most of the criteria are similar to the criteria used in the first phase development. Primary Use: Residential community -The primary use of the site will be a residential community for 5,000 prople at full development. -The following supporting facilities are included: -Primary schools -Community center playgrounds -Parks, -Markets -Sewage treatment plant Target Income Groups: Moderately low to upper -The development will upper focus on moderately low income sectors categories income levels of of low to the in Bangkok. -To better illustrate the point, study the low income it is important to the target group as income and employment status as follows: -Subsistence level Unemployed: 1: semi-employed no or very little savings; -Subsistence level 2: Full-time employment: 52 (casual labor) no family stability some savings: developed family life: income range less than 1,500 baht/month 3: -Subsistence level Same as subdsistence level 2, except income range between 1,500 baht/month to 3,000 baht/month -Income level 4: Income range from 3,000 baht/month to 5,000 baht/month -Income level 5: Income range from 5,000 baht/month and up N.B.: 1977: G.N.P per capita in baht/year. Income per capita of Bangkok Metropolitan area in income level and 1976: over 10,000 baht/year target group is composed of subsistence level The 3 4, which and 8.86. of the total 42.16% US$410 or 8,200 constitues respectively Klong population in the Toey area. The target of 3,000 target aforementioned groups will be the rehabilitation in the project. The remaining units will come from low income people in other areas of Bangkok. It is recommended that subsistence level 53 1 should be allowed to stay where they are now, or be relocated within initiated social as in sufficient the Subsistence 2 level NHA "site and service" should core be and complementary policies of upgrading improvement. relocated plus suitable training programs, should and employment upgrading, Slum area. the be house project on the periphery of Bangkok. Income level 5 can get to housing in the private access sector without much trouble. Tenure: Condominium ownership or rental -The development will offer two options of tenure with primary emphasis on condominium ownership. Rental is also possible. I Intensity of Land Use: High Density -The density planned for the site is the same as in the first phase which is 1,700 persons/Ha. Financing Mode: Public -Public financing is needed to carry out the development. -It is suggested that, though the budget has not been set up yet, the study of the hardware solution should be geared towards a scheme that would ease financial investment difficulties, i.e., the most economical provide feasible solution at optimal 54 exploitation of innovative design and procurement methods (i.e., application of approach). 55 the systems 2.2 OBJECTIVES A series of objectives has been set up as follows: -To increase space adaptability in order for the plan to be reorganized in response to dweller preferences including the possibility for expanding the unit in an orderly way. -To improve the performance of buildings and building subsystems in response to users' feedback requirements. -To reduce the costs of ownership: construction, operation, and maintainance. -To provide equal performance for lower cost or better performance for the same or lower cost, when compared with conventional construction types. -To improve physical comfort and privacy within the unit. -To eliminate inadequate ventilation. 56 CHAPTER 3: PROTOTYPE & PROPOSED CONSTRUCTION SYSTSEMS 3.1 DESCRIPTION OF SELECTED PROTOTYPE 1) prototype is a five storey concrete building, each The one consists of Fig.3.1). (see Each unit is comprised of a bath refuse a supposed be capable of being subdivided into living, dining, sleeping spaces. Service cores, which consist of of room, a balcony, a multipurpose room, which is kitchen, to 100 dwelling units or 20 units on each floor and staircases, chutes, and water tanks, are generally at both ends the building. Nevertheless, the positions of the service elements are subject to change from situation to situation, for example, two buildings may share the same staircase. The following information is the official description of the prototype in terms of function and structure: ,,Functional Area 1. Corridor 5.22 sq.m. 21.21 sq.m. 2. Multipurpose 3. Kitchen 6.21 sq.m. 4. Bathroom 3.51 sq.m. 5. Balcony 5.22 sq.m. 36.18 sq.m. Total 57 Structure System of Construction: Foundation Conventiional post & beam R.C. piles, capacity 35 (support): ton/pile Material Structure: Cast-in-place reinforced concrete Ground floor: Precast concrete component; "T" Upper floor: External wall: Party wall: beam with filler ditto Concrete block ditto 58 blocks inverted 3.2 PROPOSED SYSTEMS OF CONSTRUCTION 2) 3.2.1 Conventional System Figure 3.2: a. Structural System and Enclosure conventional The precast consists beams floor concrete composite type. The precast of precast, prestressed concrete inverted with floor filler blocks in-between. The blocks isolated is a pile foundation with cast-in "T" filler act as form-work for the concrete topping. foundation walls structural system is composed of columns and beams. The floor system is of cast-in-situ a Conventional System The place footings. The internal and external partition are hollow concrete blocks. The roof is a timber frame covered by corrugated asbestos cement sheeting. b. Method of Construction The piles construction commences with the driving of which are made of precast, prestressed concrete. 59 are driven by drop hammer. After the Piles excavation and the erection of form-work, footings are cast. Grade beams are columns and then are and constructed subsequently followed by first storey beams. Seven days after the first storey beams have been cast, the first floor begins "T" inverted to take beams shape, on the first placing by starting The beam. storey the beams are done by two men placing and adjustment of at both ends. During construction, the beams have to be deflection. shored at mid span to prevent temporarily The floor filler blocks are then put into place between the beams. two topping floor is then applied, followed by the pouring reinforcement of On top of the blocks, concrete topping and floor finishing respectively. forming and casting of the second floor supported columns and beams are then executed and are succeeded by placing and casting of the second floor The the Similarly, the remaining third to fifth slab. floor are constructed in the same way as the second one. The roof is built after the fifth floor is finished. The partitions, any carpentry and finishing work can begin wall at time as soon as the second floor is finished. This construction method is currently practiced housing projects of the NHA. c. Advantages and Disadvantages 1. Advantages of the system 60 in most a) The system requires few Low investment: pieces of mechanical b) equipment. The use of Labor intensive: labrr in the system is favorable to the smployment situation c) in general. High structural stability: Since the system employs a monolithic cast-in-place structure, the structure is very stable. Since the system is d) More competitive bidding: well known to most of general there are many potential contractors, bidders, and gradual cost reduction is likely to be achieved during the bidding process. 2. Disadvantages of the system a) Long construction time: It takes approximately 10 months (see Fig.3.3) to complete each building of walk-up apartments, provided that the management is good. Normally, it takes 1 year for a building to be completed. b) Skilled labor requirement: Skilled carpenters and masons are indispensable for this type of construction. 61 TIME (Month) 2 0 4 10 8 6 PILING EXCAVATE FOR FOOTING FOOTING FORM & CASTING GRADE BEAM COLUMN ERECTION ------------ . . ... . . BEAM ERECTION FLOOR ERECTION 1st FLOOR WALL BEARING EXTERNAL WALL ERECTION WALL WALL PARTITION & CARPENTRY ROOF PLUMBING ELECTRICAL WORK EXTERIOR PAINT INTERIOR 'AINT Figure 3.3: Bar Chart Schedule of Conventional d. Notes on Related 1. System Issues Contractors: general basis. of construction The contractors on NHA projects a Also, precast supplied and erected by their 62 done compeititive The supply and driving of suppliers. is floor by bidding piles are done by components manufacturers. are Component System 3.2.2 Small It III I Figure 3.4: a. Structural The Prefabrication) (Partial Small Component System System and Enclosure structural two into can be divided system parts: 1. Service core: The cast-in-situ elements 2. beam, are conventional last of structure the service and column, core stairs. is These constructed in the same way as the (see p.55) described in the method part. The dwelling area: Its structure load-bearing concrete column-supported composite continuous is composed of block corridor a reinforced, wall with and a precast concrete floor. The foundation is a cast-in-place beam footing, 63 resting on piles. Concrete blocks laid on footings and the precast floor is placed on the block wall when reaches a external wall, full and storey height. partitions conventional b. are are The roof, similar to it the system. Method of Construction The the construction of the foundations is similar to conventional (vertical method, except that dowel bars reinforcement in concrete blocks) are placed in pre-determined positions when the footings are being cast. The footings mortar horizontal and blocks bars are then put on top of are laid on the the footings joints. Both horizontal and vertical with joints are about one centimeter thick. After the first two rows of blocks have poured and been laid, compacted the grouting mortar into its place by will steel Horizontal bars are then placed and followed laying bond beam of reinforcement of the floor conventional done by units. After that, is placed and grouted. The slabs is done in the same system. conventional bearing wall blocks are being fabricated. c. Advantages and Disadvantages 1. Advantages of the system 64 rods. by bond the beam construction way The service core which methods is installed be as is while the also the a) Low investment: Little mechanical equipment is needed. b) Shorter time in construction: The total construction time for this building type is about six months c) (see Fig.3.5). More efficient in terms of form-work and scaffolding: The system eliminates the off and on problem of form-work and scaffoldings. d) High performance of party walls: Concrete blocks provide sound absorbtion and also possess heavy thermal mass to absorb heat from the outside. 2. Disadvantages of the system a) Close inspection and supervision are required since most craftsmen are not familiar with the system. b) Difficult to repair since the wall to the structural c) is subject load all the time. Rigidity in planning: There is less flexibily in spatial arrangement. d) Structural safety is not good: There is a risk of progressive structural collapse due to local structural failure. 65 TIME (Month) 2 0 PILING 6 4 8 10 ON EXCAVATE FOR FOOTING FOOTING GRADE FORM & CASTING BEAM COLUMN ERECTION BEAM ERECTION 10 FLOOR ERECTION 1st U UN FLOOR WALL BEARING I U WALL ERECTION 0 a 0 0 N UN EXTERNAL WALL WALL PARTITION & CARPENTRY ROOF PLUMBING ELECTRICAL WORK EXTERIOR PAINT INTERIOR PAINT Figure 3.5: d. Notes on Related 1. Component System Bar Chart Schedule of Small Issues Contractors: In most number order to undertake the construction efficiently of and factors economically, which deserve attention from masonary contractors in there tasks is a particular this type of construction. a) Work Repetition: Prior to bidding, masonry contractors should realize character of the work and minimize the requirements of b) the repetitive scaffoldings. Material Handling: Material handling is a challenging task in multi-storey construction and it not only is suggested that masonry contractors consult with 66 general contractors, but also with Experience their block suppliers. (from the construction of NHA prototype buildings) indicates that it is helpful to procure the exact amount number and types of blocks and required for each room and correctly estimate contingencies for handling and waste. Thus, accurate material estimating is a must to reduce waste and cost. c) Pre-assembly of elements: Repetition of work in multi-storey building makes possible the pre-fabrication of some elements, such as lintels. d) The most important issue that should bear in mind is contractors the provision of qualified site supervisors for the job times. 67 at all 3.2.3 Prefabricated Post & Beam System Figure 3.6: a. Post & Beam System Structural System and Enclosure The structure of the building is comprised of precast concrete beams, columns, and floor panels. The columns are over for continuous over two storeys the third floor level. are reinforced They are designed that way ribbed concrete slabs. The done on site as well), partitions precast in walls are and are panels in a plant The (it can be if there is any. Internal walls are small reinforced concrete panels the plant. Method of Construction Starting similar a external precast prefabricated with carpentry work b. spliced the purpose of ease of shipping and handling. floors and and cavity from the foundation, to the conventional method construction (p.59), except that seat and dowels have to be provided 68 is in the in footings to order columns the connect to the foundation. Columns are then erected by a mobile crane. by the positions of the dowel bars, the columns Guided put are then into their proper positions. The columns strutted and connected to each other by means by erection. beam Welding are of and bracing, followed grouting facilitates the connections between beams and columns. After the connections are finished, floor and wall panels are lifted to their positions. It requires m. at working radius 12 (capacity 2 t. three mobile cranes and height 18 m.) in order to produce six dwelling units a day. construction This Thailand Nevertheless, before. constructed in method has never been used a similar some way by in buildings were method with this cast-in-place columns instead of precast ones. c. Advantages and Disadvantages 1. Advantages of the system a) Short time of construction: The construction process is simple. Also, building components are light, so they are easy to transport and fabricate (see Fig.3.7) b) High quality of end product: Quality control processes can be effectively implemented during production in the component 69 manufacturing plant. c) Independent from weather condition: Construction can take place in almost any kind of weather. TIME (Month) 6 4 2 0 8 PILING EXCAVATE FOR FOOTING & CASTING FOOTING FORM GRADE BEAM COLUMN ERECTION a 0 BEAM ERECTION FLOOR 1st bm N S U N 0 N Im ERECTION FLOOR WALL BEARING WALL ERECTION 0 N I.0 EXTERNAL WALL WALL PARTITION H N & CARPENTRY ROOF PLUMBING ELECTRICAL WORK I I EXTERIOR PAINT INTERIOR PAINT Figure 3.7: 2. Bar Chart Schedule of Post & Beam System Disadvantages of the system a) High investment: equipment The investment in plant and is inevitably higher than the two methods mentioned earlier in order to implement this method. b) Difficulties in transportation: Prefabricated components are more difficult to transport compared to lighter or smaller materials 70 10 (especially loading and unloading). d. Notes on Related Issues 1. Contractors: Since investment, substantial capital needs this construction method requires to given to the contractors be clients or government). be The construction. and large support (from number of units ought "breaking-in" and "learning curve"). Any of the be should system contractor who be to recovery enough for a reasonable investment schedule mass regular term contract the the A prototype building should and tested prior to constructed long-term, financial high (i.e., plans to undertake this construction method should have some past experience Furthermore, management component in precast concrete technology. the contractor must provide a system in order to decent coordinate production in the plant and the the ongoing construction on site. 2. Manufacturing: Basically, Manufacturing those made there are components on the two made in the factory construction reasonable economy of scale production in a permanent 71 alternatives: site. and Given a (say 2,000 units/year), factory is more than on-site production and thus economical provide system would justification for the introduction of in the long run. the In this case, the proposal is focusing only on the manufacturing in a factory. 3. Transportation: The is transportation of the precast to be done by low-bed trailers. Small and components, are in to be transported in trailer a units horizontal This also applies to columns and large external panel an flat such as floor and internal wall suggested position. The components walls should be beams. conveyed up-right position. This would require trucks to enable the production dwelling units a day. 72 of four six 3.2.4 Prefabricated Panel System Figure 3.2: a. Structural The Prefabricated Panel System System and Enclosure system consists of load-bearing cross-walls and floor units. The bearing walls are precast concrete walls of about 4 m. width. The floor slabs are precast ribbed slabs. The external walls are precast reinforced concrete and prefabricated in integral carpentry and finishing. Foundations are pile foundations structure the with of b. beam complete with footings. the service cores is similar to that dwelling also cast in cast-in-situ a plant area. The stair flights and landing The of are the factory. Method of Construction The the (see foundation work is done in the same manner as foundation p.68). of the partial prefabrication method The first floor walls, which have to be as cast the on footing with assembly in placed bolts the center These assembly bolts will control position. line are possible in relation to the foundation, as rigid very of walls. The sequence in panel erection is process, since it this in crucial gangs fabrication to attain a high the enable must of rate work progress per shift. It requires two mobile tower cranes (capacity 4 t. at working radius 20 m.) order to method has never been used in in build eight units a day. This construction Thailand before. c. Advantages and Disadvantages 1. Advantages of the system a) High speed of erection: The construction procedure involves a small number of components, elements, and construction tasks. Thus, with the help of moderm means of mechanization, construction can proceed at a very high speed b) (see Fig.3.9). High quality end product: Quality control and supervision can be effectively controlled and implemented in the manufacturing plant. c) Independent from weather conditions: Construction can proceed in almost any kind 74 of weather. d) High performance product: Thick panels provide excellent sound insulation and possess heavy thermal TIME mass. (Month) 10 6 4 2 0 PILING EXCAVATE FOR FOOTING FOOTING GRADE & CASTING FORM BEAM COLUMN ERECTI ON BEAM ERECTION FLOOR ERECTI ON 1st wo FLOOR WAL L BEARING WALL ERECTION EXTERNAL WALL WALL PARTITI ON & CARPENTRY ROOF PLUMBING ELECTRICAL EXTERIOR WORK PAIN T INTERIOR PAIN Figure 3.9: 2. Bar Chart Schedule of Panel The disadvantages of a) High investment: System the system High investment capital for panel production plant and equipment, on-site and/or off-site b) is required. Difficulty of transportation: Large panels are difficult to transport, and especially difficult to load and unload. pc) Unreliable structural 75 safety: There is a risk of progressive collapse resulting from local structural structural failure, due to the and joint characteristics of the structure. d. Notes on Related Issues 1. Contractors: system The same qualification of contractors as for of level requires, at the least, the the prefabricated post & beam method. 2. Production: It is more or as the post & beam method, in terms of the also, prefabricated less, the same justification of the system's implementation. 3. Transportation: The done transportation by low-bed internal upright panels trailer. The and external, wall units, be loaded as position and position should the manufactured finally efficiency on order to be vehicle in the since it is better assembled. Also, correspond to the final fabricated. This will in both transportation and 76 is both are to be transported in position. It is suggested that all of position when of all precast panels an the same in the position ensure high fabrication at the same facilitate time. It requires five the production of day. 77 8 trailers dwelling to units in a 3.3 COMPARATIVE COST ANALYSIS The relevant determination of (time-dependent cost quantity and components as follows: a. Labor b. Materials c. Investment d. General e. Transportation f. Overhead takes expense 78 into account dependent) all cost 3.3.1 Cost Determination cost for each method is estimated on the basis The the cost of a building in a project of units. into taken 100 standard dwelling development tax, expenses, in The following are the ways account. and not are constant for any method, have which profit, land cost, Land of been which costs were determined for each method of construction: a) Conventional Method The cost estimate is composed of 2 parts; unit costs. Quantity and take-off take-off quantity includes superstructure, and finishes, it is then substructure, the unit costs. The price of labor is multiplied by calculated in relation to units of materials, which is practice in Thailand. Five percent is added common quantity of reinforcing steel the total and wastage. Also, 7. for is provided for to splicing concrete and mortar, and 5% for concrete block, for wastage that may exist and at in the process. Overhead costs include fees for engineers, foremen, and staff on site and headquarters, expenses can preparation of salaries be during construction, broken down into etc. cost General of site and power and water consumption. The cost investment is the cost of form-work, equipment, and tools. b) Small Component Method The cost estimate of 79 this method is similar to conventional c) cost practice. Prefabricated Methods The total transportation overhead costs. foundation up electrical costs, general of expenses, and Construction can be broken down work, architectural cost of these methods is made costs in the factory, construction costs on production site, cost (Post & Beam and Panel System) fabrication finishes work, and into erection, mechanical work, work, and sanitary installations. The items main which have been taken into account can be outlined as follows: 1) Plant & production cost analysis: A model of the plant necessary for the construction of a prototype is assumed, and the cost of plant and production can be derived from its analysis. The interest rate assumed is 13"4 2) Construction cost on site: The cost of foundations, erection, 3) and fabrication. Transportation cost: The cost of five trucks to facilitate the production of 8 iv) Overhead cost: units a day. Expenses of salaries and fees for engineers, staff, in plant and on site. 80 3.3.2 In the Cost Comparison the final analysis, the comparison indicates construction cheapest component by the prefabricated panel method is one, followed by prefabricated post & beam, (partial prefabrication), that and conventional the small method respectively. Other noteworthy remarks are: -The total cost per dwelling unit, referred to the one built by conventional small component method method as 100%, is 97.6% for the (see Table.3.1), 94.6% for the prefabricated post & beam method, and 93.6, for the prefabricated panel method. -A cost component breakdown shows that, for different methods of construction, labor is about total cost (see Table.3.2), 12-16% of the materials 73-78%, investment 4-6%, general expense 1-3%, overhead 2-3% and transportation in prefabrication methods 1%. -The total material cost per dwelling unit, if one assumes that conventional method as 100%, is 100.6% for the small component system, 99.5% for the prefabricated post & beam method, and 99.3% for the panel thus are almost the same for each system method, and (not to mention savings due to speeded up erection time). 81 Prefabricated Prefabricated Panel Post&Beam Conventional Small Component Total Labor 100.0 101.2 72.0 76.8 Materials 100.0 100.6 99.5 99.3 Total Investment 100.0 64.7 129.8 105.6 - - Cost Component - - Transportation General Expense 100.0 97.6 26.7 20.7 Overhead 100.0 57.0 59.6 59.6 100.0 97.6 94.6 93.6 Total Cost Breakdown of Construction Cost Components Table 3.1: Cost Component Conventional Small Component Site Prefabricated Panel Prefabricated Post-Beam Plant Total Site Plant Total Labor 14.9 15.5 8.8 2.6 11.4 10.5 1.7 12.2 Materials 73.7 76.0 42.0 35.5 77.5 48.0 30.2 78.2 - - - 2.0 2.0 - 1.5 1.5 Equipment 2.7 2.3 2.8 1.6 4.4 1.9 1.2 3.1 Formwork 2.9 1.4 0.7 0.5 1.2 0.9 0.8 1.7 3.7 - - 5.6 - - 4.8 - - - - 1.0 - - 1.0 3.4 3.4 - - 1.0 - - 0.8 - - 1.5 - - 1.5 Investment: Factory Total Investment Transportation General Expense Overhead Total Cost 5.6 2.4 1.4 100.0 100.0 Table 3.2: 100.0 Comparison of Cost Components 82 100.0 DESIGN CHAPTER 4: 4.1 APPROACH General Criteria for Housing Construction Systems Selection in point users or the same user at a different Different varied time have varied needs. In order to satisfy such needs or various categories of users, and for the purpose of by responding to those needs dwellings producing various methods of construction, two alternatives exist: 1) A system of construction employing physical elements that can be changed by the user without interfering with the main structure and its integrity. 2) A system of construction with no elements that can be altered by the user. This is the most prevalent approach to housing design at the present, not only Thailand, but throughout the world. The NHA employing the second is alternative, which results in the limitation of most users'choices, since housing stock ability to limited. is not large enough, and thus the the users' move from one housing type to another, is also This does not mean that the user is not allowed to rearrange his furniture), but unit at all the (for example, he can change fact is the extent, to which he his is allowed or limited to make needed or desirable modifications to his house, suggests that his varied 83 needs cannot be by accomodated all the ever changing users' needs in the Ideally, to from the beginning. process design in incorporating of lack present solutions. The reason lies accomodate needs, original stock of dwellings would have to provide a wide range of selections of many diverse designs, allowing the user to move from one dwelling to another, as his needs and requirements In addition, the stock housing case for such mobility. This, however, is seldom the allow to have to be larger than effective demand, would offered change. or rarely possible, since users generally are unable to move earlier as a number of reasons, and the housing stock, for around is not and will hardly be mentioned, than larger effective demand, in the foreseeable future, particularly in Bangkok. Due and to the existence of an insufficient housing the subsequent severe limitation on users' mobility, an approach, alternative even stock expand his own which allows the user to unit is more preferable change in such or a situation. Given the possibility to change his dwelling, the user should different another, be spaces remove able to change the relationship as he wishes; he can open a or relocate a partition, decrease the dimensions of a space, and so on. 84 door, between close increase or 4.2 NOTES ON EXISTING SYSTEM Insofar allowing as the characteristics the first alternative is concerned, participation of the user in i.e., changing the of his space, the system does not allow any modification on the part of the user, once all elements have been fixed in the design, and during construction. The user is thus confined to a fixed layout of territory and, to some in his own unit in terms extent, space configuration. Consequently, the following impediments to adaptability and extensibility arise prototype -It in relation to the existing standard (see Fig. 4.1): is difficult and sometimes impossible to remove a wall or partition, even non-structural ones. -The distribution of structural reinforcement in the floor does not allow for the relocation of any wall partition or (a heavy one). -The distribution of electrical, water, and sewage outlets does not allow for the relocation of functional spaces, such as kitchens and 85 bathrooms. 0 0 LJ E gr Figure 4.1: t 00 Prtoy L1 ll U Existing Prototype of Dwelling Units 86 4.3! "SUPPORT-DETACHABLE UNITS" APPROACH TO HOUSING 1) In order to investigate better ways to deal with the problems of the design and construction of mass housing, nine Dutch architects and a representative of the Dutch Architects Association formally founded the SAR (Stichting Architecten Research) in 1964. As a result, a hypothesis was developed on the conviction that large scale industrialization of the housing process can be developed successfully, if production and use are realized as two distinct "spheres". The collective sphere is represented by the "support structure" which is seen as or referred as a long-term investment and is made, as well as, decided upon by the community to contain a given number of dwellings and thus constitutes a collective infrastructure, i.e., the "support". The support may or may not be the result of using systems building and responds to professional decision making. The other sphere is represented by the "detachable units" which are the elements for internal layout and servicing of the dwellings in the support structure. These element are industrially made products, durable consumer goods subject to change by decisions of the user. 87 Each sphere has its own rules of production, planning, and design. The actual individual dwelling is the result of "detachable units" being placed in the "support" structure. In conclusion, the SAR methodology (as generally known) is a tool to allow for a more open-ended approach to plan, design, and conceive mass housing schemes by assigning those decisions made by the community to the realm of while decisions made by the individual by the "detachable units" or "supports", dweller are satisfied "infill". The methodology is based on two objectives, i.e., dwelling can truly reflect personal a aspirations only when the dwellers are able to make their own decisions on the level of the plan and equipment of their dwelling, and the participation of the residents is critical in the exploitation of the potential of existing technology to accomodate change. Accordingly, three principles for the design of supports 2) took shape, as follows: 1) Each dwelling unit in a support must allow for a number of different layouts. 2) It must be possible to change the floor area, either by additional construction or by changing the boundaries of the units within the support, or by manipulating the layout as such. 3) Supports or parts of a support have to be adaptable to non-residential functions, such as office space or 88 shops. is not necessary that every support it However, have to satisfy all approach aims at a complete, fixed, and finished unit. This has as providing a these criteria. regards Thailand, the conventional As result the rigidity of planning, relatively high initial levels all of adaptability to almost lack and cost, will of change. criterion (i.e., to the most critical user requirements, in terms of space. The first criterion of support principles, is flexibility, will help in increasing the choice that the an additional of configurations which were once partially fulfilled planning by the conventional Moreover, it second to change the floor area) mentioned above is possiblity answer the outset, the In approach. since the dwelling process is should be-as dynamic and changing in the it approach, construction also not enables the analysis of only from the point of view considered-as support-infill the dwelling of finished unit cost but from the viewpoint of stages of completion and finish variable between space and finish, or possibilities, e.g., trade-off and and equipment, etc. Cost is then considered can be assigned to various stages as well 89 a as levels of completion as the situation may various require, is likely to be a more realistic approach to low-cost which housing in developing countries, than what is being implemented at the moment. Last but adaptability answer sort viable not least, the third criterion (i.e., to non-residential functions) will provide the to problems of urban decay if rehabilitation of is necessary. In brief, the support-infill in the Thailand context in terms of a design any approach is approach, since it responds to the requirements of both individual and community in many respects, which are practically absent in the conventional approach. 90 4.4 TRANSFORMED SYSTEM From and a survey of user requirements (see Chap.5, additional require for, space for the accomodation of additional the issue of expansion, affordable for on the Although dwellers are to prepared invest house, either for their the user. the use, own of subletting, usually only limited savings are available this It task. in designed suggested that the is such a way that only a elements, to accomodate expansion, will done, effort, provision for The If this minimum of which means that the initial cost of cost of expansion, expansion itself, will be variable be provided. the user can enlarge his unit with a construction the of or for should support minimum the in enlargement is or or belongings, the emphasis of the support should be people then call the assumption that the user will given 5.3), as well as the be kept to a minimum. dicussion above exemplifies the design of supports as a matter of optimization. The problem is, how to generate the setting for a desirable greatest variety in lifestyles and personal preferences, by using as few "detachable" units as possible. cannot three If we consider the support as be changed, examples elements (since it is comunity product) then (see Fig.4.2) can be considered kinds of support structure. 91 as that the three ((c) (a) aI0 13 0 Figure 4.2 The NHA, first the second one elements, provides and rigid, for certainly (b) third example), possibilities which support vari'ty in terms of planning is clearly few variable elements. It changes that may be will required; any direction whatsoever. At too much is made variable (as in the money and effort will be wasted in providing in excess to what is necessary. obviously, is the middle path. solution, for that the The first example cannot be extended in other extreme, if is (c) one not accomodate any the elements the there are too unit economical optimizes and expansion. the support, the is the support which third the a prototype unit provided by unlimited range of an configurations too is (a) one may The second It also is the most it provides the requisite variable eventually be adapted, as future needs. 92 required by 4.4.1 Design Proposal The basic original plan unit represents (Fig.4.3) the minimum elements required to accommodate the plans to shown be as shown below support is in the following pages. It is adapted plan of the prototype the (the width of a new proposed the same as the original, exceeds the original from but the length of a new one by 15 cm). Figure 4.3: Proposed Support Structure It solution or possiblities principle support be noted that the proposal should alternative for available, for optimization,' any given i.e., are there the support plan proposal. has to be realized, i.e., only is not the several However, one the design of an actual income category is a matter of to provide the greatest possibile range of options to satisfy the basic affordable dwelling needs of a of target income group supports, see (for further reference of the "Variations: 93 The Systematic design Design of by N.J. Supports", Technically, and support coordinated conventional on both the spatial original either by means and infill, support capacity of the integration its modular order should facilitate a good between the Habraken.). of modularly or by ones. Fortunately, the dimensions employed in and produced industrially elements, plan of the prototype are, more or less, based standard modules, e.g. the width of each unit is 3.60 m. So, it is not so difficult to adapt the prototype dimensions for a new proposed unit and use these dimensions as a viable integrating Fig.4.4) dimension for both support and infill (see The 90 cm. module coincides with the basic modules currently used in Thailand, namely 10 cm. and 30 cm. Figure 4.4: Proposed Prototype of Dwelling Units 94 4.4.2 Combination of Dwelling Sizes & Staging Process To the illustrate of combination floor efficacy areas below of the (Fig.4.5) the proposal, an represent assessment of the capacity of the support to accommodate the of mix dwelling sizes for varied user various and needs requirements. None the less, this does not mean that all the options listed here will need to be implemented. Normally, I to 2 of modules support sectors seem to the be most applicable in this project. Figure 4.5: Regarding adaptability simulated ------ - --- - ----- ........ 1.. 4 ........ .... :, 1 ~~... :::::::0..... ~ ::::::::: ~~ ~~ ~ ~ ~ ~ ~::::::: 1 . -... ::::: Combination of Dwelling sizes the objective to increase the possiblity for and staging expansion, process the following will exemplify example the of capacity vis-a-vis this objective of the new proposed support plan. 95 a Phase 1: This represents, theoretically, the basic support as a minimum dwelling to be occupied by users. site I I However, depending on income level or economic capacity, it may include more elements than shown here. It is possible for users to buy or rent just this basic support. Fig. 4.6 (a) Phase 2: Since the basic support sufficient for occupation, be the which is NHA will basic unit provide In will a a The finishes inside 96 it each kitchen, and back depending on However, initial have a toilet and front some general, (with bathroom), (b) likely to the case for this project, occupation. 4.6 not immediate infill elements for Fig. is facade. vary income level. is also possible if a user does not want the infill elements from the NHA, he may wish to add infill elements on his own, from the very beginning. Phase 3: for Partition a bedroom with a door has been added. Painting and other finishes (if there were none) have been Fig. 4.6 (c) completed. Phase 4: The kitchen is extended to the balcony area, giving more interior space to accomodate a sofa. The family may gain a new born member, the bedroom starts to be a little crowded. Fig. 4.6 (d) 97 Phase 5: The user manages to acquire a space from an adjacent unit (either by renting or purchasing). Thus, it enables him to have a big master bedroom. The new bedroom is, clearly, less crowded. The space which was once a bedroom Fig. 4.6 (e) has been changed into a spacious living room. Phase 6: This is normally the last stage for a nuclear family in big cities. The unit, now occupies two modules of the support, accomodates a master bedroom, two bedrooms, a living-dining space, a Fig. 4.6 (f) kitchen, and a bathroom toilet). 98 (with 4.4.3 Support Element Options The possible Support Element Options shown below represent four alternatives (see Fig.4.7), and take into the previously proposed systems of construction 3). Clearly, feasible. a many other solutions are account (see Chapter possible and/or However, the proposed systems of construction, to certain extent, are designed in compliance with available technology and also based on components in the country. 99 available industrialized Figure 4.7 As a result, in terms of construction, we have the following four support types: 1) Conventional System: The system is composed of cast-in-situ columns and beams. The floor system is of precast concrete composite type. The internal and external partition walls are hollow concrete blocks. The roof is timber frame covered by corrugated asbestos cement sheets. 2) Small Component System: Its structure is composed of concrete block walls with reinforced concrete 100 lintels. The roof and floor system are similar to the conventional 3) Prefabricated structure of system. (R.C.) Post & Beam System: The is comprised of precast the support concrete beams, columns, and floor panels. The internal walls and partitions are small in plant. The roof concrete panels, precast of modified floor panel (staircase, e.g.) 4) reinforced is made slabs. Service cores are also prefabricated. Prefabricated Panel System: The system consists of load-bearing cross-walls and floor units. The bearing wall panels are prefabricated in plant transported to the site. The floor and roof are precast ribbed slabs. The stair flights landings are also cast in 101 the factory. and slabs and Elements Infill 4.4.4 support economical that elements are be will one most essential most and best the speaking, Generally provides which providing for basic shelter needs at an affordable price, in the first place. Those which can be added later are elements finished or made by the dwellers "infill" or by means of later stages of building themselves activities. so-called "infill" The elements represent, by to be provided by the user after taking possession of the "support". the those all definition, items Nevertheless, which are in this case, since may not be acquainted with this notion and, public in most case, users want to occupy the unit as soon as possible, some infill by the include (see NHA elements will in the first bathrooms Fig.4.8). In place. be provided These and the front and back keeping with the elements facades notion of flexibility and extensibility, it is suggested that such that, elements should be provided in such if possible, they can be re-used again Chapter 5, 5.3). 102 a way (see Figure 4.8: It Infill Elements provided by the NHA should also be noted that, an infill element is not necessarily temporary. It may be as permanent as the support structure. The difference lies in the decision making power, although user can it is made of reinforced concrete, as long as decide its location, it is definitely element. 103 an the infill 4.5 TENURE POLICY Insofar as flexibility and especially extensibility are the adaptive design of the layout aspects concerned, is not enough appropriate potentials tenure implementation. system of In addition, policy is also required to exploit an the of flexibility and extensibility of planning. In words, a planning concept is of other the for alone little value, if the tenure does not allow change to happen. Therefore, system of tenure should accomodate the expansion of the units, whenever the situation calls for it. Suggestions on this matter are as follows: -Dwellers can buy one, one and a half, two, or more support "sites", on a hire-purchase basis in the first place. -Dwellers may occupy all units after purchase, or they can occupy just one unit and "hold back" the rest for future extension. The spare unit may be sublet with the help of the NHA. -The subletting terms should be bound by signed and legally valid contracts. Dwellers who need more space, can expand the unit by simply not renewing the sublet contract. -Dwellers who remain on a subletting basis could be relocated in new projects or available spaces within the project, to accomodate expansion or 104 change for the original owners. -The NHA could try to locate rental units in-between purchased units in order to allow for the possibility of buying adjacent units, whenever money is available, and needs for expansion arise (in this case, the sublet units are owned by the NHA) -Dwellers who own the units have the priviledge to buy the adjacent units first, if the unit becomes available. These that suggestions are based on the assumption the NHA will and some infill the first provide standard units (support elements for initial occupation) in place, and that there exclusive modification other than that. 105 will be no PERFORMANCE & EVALUATION CRITERIA CHAPTER 5: 5.1 PERFORMANCE CONCEPT the designer's knowledge has been based Traditionally, on between correlation should wall would If the designer had to decide that provide privacy between adjacent bedrooms, solution. design The aspect known usually acquired through long and direct experience of alternative on solutions and thus he could decide he was "benefit" of a determine to weight cost against benefit of the wall best the a given design solution and implicit or needs. user explicit material direct the of knowledge empirical his empirically the particular type of wall construction which should be chosen and which would provide what he wanted, while another did not. Scientific measurement of acoustical seperation was since unnecessary, his direct experience of what material (design) could assure what acoustic "quality" he was looking for, not the measured acoustical performance of the wall. However, such a formulation of design knowledge has its shortcomings, particularly with the introduction of untested new which materials and methods. For example, express the need for safety in building terms of codes, specific design solutions, become rapidly outmoded by new or changing technology. materials, Thus, new the application of new products forms of tendering, the rationalization 106 and of and building efficacy of The internationalization of the traditional influence of the needed beyond the are of building performance may concept the are approach. the behavior of a person with construction, since they approaches, new for calling the internal and in action. Both external compared be respond under conditions. The more and/or required responses of be can buildings programmed, the better performance criteria can be stated to achieve these performance responses. In doing so, the concept allows us to formulate our resources from which the building to the value system of is of guiding of knowledge the assembled and relate it the building's user. In the conventional prescriptive approach, the physical design specific of the project, buildings are defined types of construction and materials. in terms of In contrast, or performance concept is an organized procedure "The state the it is possible to within which framework desired attributes of a material, component, or system, intended in order to fulfill the requirements of the means to be to the specific regard user without employed in achieving the results." 1) In more specific terms, J.R.Wright mentions that "A performance statement, according to the National Bureau of Standards, has three essential parts--Requirements, Criteria and Test... A requirement is a qualitative statement which identifies a user need... 107 a qualitative When possible, the Requirement, statement, is converted to a quantified statement which provides This statement Criterion. is -ed the with the compliance for attaining levels specific intent of the Requirement. statement of the performance Test portion The indicates the method of assessing materials, components or systems for compliance with the Criterion... of as be thought Criterion levels must is because of two tentative. This indeterminately prominent aspects of performance: 1. The final level of or the performance required of a material, component system depends on its inevitable interaction with other materials, components and systems, and 2. Desired performance levels are continually subject to change due to the information feedback mechanism that is part of the performance approach." 2) In short, the essence of the performance concept is the performance basis for evaluating the suitability of building systems. The approach is an organised procedure within which it is possible to state the desired attributes of materials, or components without the what systems to fulfill the requirements of regard to any specific means employed in results. user achieving Therefore, the formulation of a statement of is expected from components or subsystems in terms of performance is requirement, feasible, made possible. The statement quantifies identifies this in the form of criterion, a if and sets the method of assessing the solution for compliance with the criterion. 108 5.2 PERFORMANCE A CONCEPT vs SYSTEMS CONCEPT approach to building does systems include the performance concept. be applied independently not necessarily The performance concept may as from a systems concept John contents: Voilett is incorrect to say that because the systems "....it of the identification involves necessary approach therefore and measures of performances, it objectives term the performance concept. The latter incorporates is only to situations in which it appears applicable precisely specify to feasible and desirable both characteristics of physical objects without measurable them. to the particular means of producing references in Such situations are by no means invariably present all building industry problems which could benefit from the performance Conversely, systems approach. the which be usefully applied to problems in concept can the systems approach has no particular relevancy." 3) Generally is most the problem is large-scale, complex, with speaking, the systems concept applicable when individual values difficult or impossible to quantify. nature the problem calls for an emphasis on of rather than the part, as well performance related on best problems to individual components, when the emphasis is more are certain whole as, on their interactions. The concept, however, is more relevant to measurable means, the The properties. In this case, ends, rather crucial. It is also obvious that area of overlap(see Fig.5.1), there than is a in which problems are addressed by some combination of both approaches which is also the case of this particular project by the NHA. 109 RANGE OF BUILDING PROBLEMS THE WHOLE BUILDING INDUSTRY GROUPS OF BUILDINGS APPLICABILITY OF SYSTEMS CONCEPT INDIVIDUAL BUILDINGS - 4 j INDIVIDUAL COMPONENTS __j? I BASIC MATERIALS & SMALLEST PARTS APPLICATION OF PERFORMANCE CONCEPT RANGE OF OVERLAP Figure 5.1: Area of Systems and 110 Performance Concept Overlap 5.3 USER REQUIREMENT & PERFORMANCE CRITERIA 5.3.1 Summary of User Feedback As problems a result from a survey done in associated 1971 by NHA, the key with user requirements in the walk-up apartment were: 1) The space was too narrow and inadequately ventilated. The units had dimensions of 3.50 m. 10.00 m. by which is proportionally narrow. Moreover, each unit had to be divided into zones, i.e., kitchen and toilet in the back, along with bed rooms and living rooms in the front. The dividing partitions made ventilation even worse. 2) Since extended family life still prevailed, and the number of children was many, the need for more or additional space was a major problem. The units were generally occupied by more people than they were originally planned for. Loft space was sometimes added by the occupants to provide more living accommodation for the family. 3) Due to the way most food were cooked, i.e., most dishes are prepared by frying, it was suggested for the kitchen to be located outside the unit. 4) Another observed but unsatisfied need was the need for additional storage space. The occupants expressed this unfulfilled need. It is very usual for this category of people to save everything that 111 may prove to be useful metal in the future. They preserve containers, boxes, pieces of wood, etc., This hoarding of miscellaneous items was not supposed to occur and was not expected to take place in the provided spaces. It certainly exacerbates the already over-crowded living conditions. 112 etc. 5.3.2 User Requirements The following dimensions, according to Tarja Cronberg's "Performance Requirements for Buildings", of user activities were chosen as the basis for formulating user requirements for buildings: 1) Which activities are performed by the user (or which activities should he be able to perform)? 2) Who performs the activity (who is the user)? 3) Which of the consequences caused by the characteristics of these three dimensions (which activities, by whom, and which consequencs) have been derived from the model in Figure 5.2. USER CHARACTERISTICS GIVEN CONDITION Figure 5.2: A Conceptual Model 113 User Activities relation to the objectives of the project In of user responses, summary which are: planning of requirements 1) there are two main concerns extensibility, flexibility and 2) the dwelling and unit. can be formulated As a as follows result, in user (Table 5.1): USER REQUIREMENT ACTIVITY USER CHARACTERISTIC(S) CONSEQUENCE(S) FOR THE USER to expand -Changing needs a) Family cycle b) Social mobility c) Locational mobility d) Change in world view e) Change in dwelling culture satisfaction of need to have more space The building should be designed in a way which enables the user to expand his own unit to meet his needs. satisfaction of need to select any planning arrangement The building should be designed in a way that the user is able to select any planning arrangement that he desires. satisfaction of need to adapt the unit The building should be designed in a way that the user is able to adapt his dwelling to meet his needs. to select to adapt -Differing needs a) Differing dwelling types b) Consumption and production influences c) Income distribution d) Social allocation policies Table 5.1: Formulation of User Requirements 114 5.3.3 Performance Requirement and Criteria obtaining After requirements performance for parts requirements, user relevant the or subsystems of can be derived. Performance requirements, by their building are formulated independently of the solution and/or nature, which material is applied to meet the requirements. When formulating the requirements, the solution is left open. performance requirement solution. does not prescribe a A specific Instead, the goals for the end result are given, i.e. what is to be achieved by the end result. At the time one the a must, nevertheless, also specify how to degree to which alternative solutions same evaluate fulfill these requirements. A transformation of user requirements to performance requirement implies: 1) The identification of performance requirements for subsystems, technical solutions and materials on the basis of user requirement. 2) Formulating the performance requirements in a way which will enable the control of the requirements, both in the building process and in the building in use. Therefore, a performance requirement is formulated with two components: 5) 1) The goal component, identifying what is to be achieved. 115 It is still debatable whether this component should be stated qualitatively or quantitatively. However, in both cases, one ought to be able to assess whether the goal Bureau of has been achieved or not. The National Standards "performance (Guide Criteria 1971) considered requirement" (goal component) as qualitative, as opposed to the term "criterion", which is quantitative. 2) The criteria component, describing how the goal satisfaction can be controlled. It provides a means for selection of a solution and control of the requirements. Criteria for performance requirements generally consist of a statement of the properties which are required of the solution objective The (Karlen, 1973) between distinguishing of the two (goals & criteria) of a performance statement is components to facilitate the evaluation of alternative solutions in the in the design phase and the quality control phase, while maintaining the links between phases of the different the transformation process. The latter is provided by the goal solution manufacturing to component, which is stated without regard to the be applied to or the given conditions applicable. Criteria, given in terms of required properties, provide the means for selection and control. Two underlying assumptions for formulating performance requirements in this way are that the criteria 116 are more easily evaluated than and a correlation between and the values of the satisfaction of the degree of the properties stated the goal goal itself, satisfaction as criteria can be established. From performance the user requirements requirements formulated earlier, and criteria for subsystems prototype can be formulated as follows: 117 of a Partition $dbsystem: Criteria Performance Requirements -------------------------------------------------------------Users should be allowed to -Living unit should be within relocate the partition expandable the units. Two semi-skilled users should be able to do this task with hand tools. -Bathroom partition should be -Living unit should be dismantled easily by a rearrangeable semi-skilled users with hand tools. ------------------------------------------------------------N.B.:The once removed, partition, should units also be designed in could be lifted excessive strain. should be re-usable. basic such a way that its by 2 healthy adults without This does not apply to partition. 118 the It any bathroom Subsystem: Floor Criteria Performance Requirements -Living unit should be -The floor should be designed in such a way that the expandable reinforcement provided shall accomodate the relocation of walls or partitions that may be changed by the users' decisions. -Living unit should be rearrangeable 119 Subsystem: Structure Criteria Performance Requirements -Living unit should be expandable -The structure should accomodate any expansion limits), (within allowable change, or modification of the space configurations that may happen without the addition of any essential structural elements or parts. -Living unit should be rearrangeable -The structure should accomodate any expansion, change, or modification of the space configuration without any deflection members. 120 in any structural Subsystem: Wall Criteria Performance Requirements -Living unit should be expandable -The party wall should be designed in such a way as to allow the users to penetrate it to facilitate horizontal expansion of the units (by occupying the adjacent units) . -Living unit should be rearrangeable -The wall would allow the attachment of another wall or partition either by conventional methods or special components without difficulty, even though the work is undertaken by the users themselves (unskilled or semi-skilled) . 121 Subsystem: Sanitary System Criteria Performance Requirements -Living unit should be expandable -Water supply and sewage taps should be located in a position that facilitates the relocation of the bathroom and kitchen within a certain specified range. -Living unit should be rearrangeable -The connection of the duct system should allow modifications due to the relocation of related facilities. Modifications to the duct system are suggested to be preferrably undertaken by skilled craftsmen. 122 5.4 SELECTION CRITERIA Decisions related to the design and construction of any building systems objectives. many different and/or criteria Each of which, one way or another, is concerned different with involve aspects of the construction industry. In order to formulate selection criteria for a decision in our case, there are three areas where special attention be paid, i.e., variables, and the program and its objectives, the the performance requirements. should context Since the aforementioned areas have been investigated and discussed in the previous chapters (Chapter 1,2,&5), a set of selection criteria or objectives \may be outlined as follows: 0-1 Improve the performance of buildings and subsystems 0-2 Minimize cost of construction & maintainance 0-3 Number of units to be built: 0-4 Unit height: 0-5 Maximize unskilled labor 0-6 Short "learning curve" * 0-7 Minimize use of skilled workers 0-8 Simple on-site assembly 0-9 Minimize finishing on site * 5,000-6,000 units 5 stories The period of being accepted in the market. 123 0-10 Maximize the use of local craftsmanship 0-11 Maximize consumption of locally produced materials or products 0-12 Minimize imported materials 0-13 Reinforced concrete is desirable 0-14 Minimize consumption of wood (includ. formwork, scaffolding) 0-15 Maximize interchangeability of components, available in the market 0-16 Minimize idle material stock and waste on site 0-17 Post & beam method is preferable 0-18 Handling on site: manual and medium to light-weight machinery 0-19 Maximize use of available technical know-how of technicians 0-20 Develop management and technical capacity of existing technicians 0-21 Endure discontinuous product line (inconsistent housing policy) 0-22 Minimize technical support from other agencies (since it is not yet available) 0-23 Minimize highly sophisticated management, but improve to achieve higher attainable level of sophistication 0-24 Handling off site: light-weight manual and medium to machinery 0-25 Road transportation: medium to light-weight 124 equipment and vehicles 0-26 Minimize initial capital investment in construction 0-27 Short term returns of investment 0-28 Minimize erection time 0-29 Living units should be expandable 0-30 Living units should be rearrangeable N.B.:0-1 through 0-4 are derived from the program and its objectives, 0-5 through 0-28 from the context variables, and 0-29 through 0-30 the performance requirements. It should also be noted that the listing of criteria basis suggested for intended were compiled on an individual the purpose of illustration. Principally, it only methodology and interpretation of above selection to exemplify thus the represents application the of the author's own of this procedure. It is obvious that a team experts -say- comprising an economist, a contractor, architect, a policy-maker, etc., series is an would most likely produce a of more accurate and explicit objectives for systems selection. Unfortunately, it is beyond the capacity of the author to organize such a team for this study. Nevertheless, for the purpose of illustration, as mentioned earlier, 125 an attempt was made to keep the selection criteria listed "generic" as possible, yet not irrelevant. 126 as CHAPTER 6: METHODOLOGY 6.1 THE 6.1.1 Individual Evaluation the procedure for a decision-support sum up, To 1) SYSTEMS EVALUATION & SELECTION in can be decision-making outlined, model step-by-step as follows: Step Step Step Step Step One Two Three Four Five - Determine the objectives - Choose the alternatives to be evaluated Decide upon a scale of Beta values Make a table for each system Give Beta-value judgements for every system with respect to each objective Give Alpha values by applying an objective weighting method, in this place, the aforementioned method of Paired Comparisons (with results normalized to a standard sum) Decide upon the aggregation function to be used Aggregate Alpha and Beta value judgements Derive overall judgement about each alternative system Compare the overall judgements for all the systems and rank them - Step Six Step Seven - Step Eight Step Nine - Step Ten To illustrate this procedure in application, we will take a simple example of a Step low-cost housing project: 1: Assuming that the objectives are: 01 - ease of assembley 02 - short erection time 03 - use of medium-weight 04 - production made in situ The choice of obviously an equipment only four objectives is unrealistically short 127 list for selection, but is used here only as an illustration Step 2: of the method. Let us assume that the choice is to be made between a large panel system and a small component system. Step 3: The Beta scale will be 1 to 9, desirable, 5 = neutral, with 9 = most 1= most and undesirable. Step 4: Construction a table for each system. Table 6.1: System A Alpha-Beta Table for System A & System B (large panel) Beta value System B AlphaBeta Alpha value Beta value 01 01 02 02 03 03 04 04 Sum of Alpha's - (small component) Alpha value Sum of Alpha's AlphaBeta = Sum of Alpha-Beta = Sum of Alpha-Beta = Sum of Alpha-Beta = Sum of Alpha Sum of Alpha-Beta = Sum of Alpha Step 5: Give Beta values for each system with respect to the objective, e.g., that a large panel system is desirable due to ease of 128 assembly (7), more desirable in terms of time of erection (8), undesirable for (4), medium-weight equipment use of and most undesirable in terms of production on site Small components will of assembly, score (4) for time of (1). (6) for ease erection, use of medium-weight equipment, and (9) for (8) for production on site. Step 6: Give Alpha values to objectives. By means of the method of Paired Comparisons we construct a matrix 1860), (Fechner, of the objectives and compare them, pair by pair, 01 01 02 03 04 1?2 173 1?4 2?3 2?4 02 2?1 03 3?1 3?2 04 4?1 4?2 3?4 Fig. 4?3 6.1 It should not be forgotten that the Principal Diagonal will be left blank, since this is where each objective is compared to itself. Let's assume that (01), i.e., assembly is equally important with 129 ease of (02), short erection time, and (04), production on site, but both are less important than (03), i.e., use of medium-weight equipment. thus, 1?2 = ties = 1?3 = no = 0 1?4 = no = 0 Similarly, for (02) short erection time 2 7 3 = no = 0 274 = no = 0 also,(O3) 1/2 use of medium-weight equipmnent 374 = yes = 1 Subsequently, all these values are entered in the matrix. It should be noted that the comparisons above fill Principal Diagonal, although just one side of the this is sufficient, since the opposite judgement may be simply entered symmetrically in the corresponding cells on the other side of the diagonal. Thus, we obtain the following matrix: 01 02 1/2 01 02 1/2 03 1 1 04 1 1 03 04 0 0 0 0 1 0 130 Fig. 6.2 By means of simple calculation, Alpha values can be obtained as follows: Alpha value Objectives 01 = 1/2 02 = 1/2 03 = 3 04 = If we normalize Alpha values by assuming the sum to be 100.0, then Rank Alpha value Objectives 01 = 8 3 02 = 8 3 03 = 50 1 04 = 34 2 Step 7: The aggregation function will be Sum of Alpha-Beta product Sum of Alpha's Step8&9: With Beta values from step 5, step 6, and table from step 4, tables will take shape: 131 Alpha values from the following Table 6.2: System A Alpha-Beta Table (large panel) Beta value (with assigned values) System B (small component) AlphaAlpha Beta AlphaAlpha Beta value value Beta value ------------------------------------------------------------48 8 6 01 56 8 01 7 02 8 8 64 02 4 8 32 03 4 50 200 03 9 50 450 04 1 34 34 04 8 34 272 -----------------------------------------------------------Sum of Alpha's = 100 Sum of Alpha's = 100 Sum of Alpha-Beta = 354 Sum of Alpha-Beta = 802 Sum of Alpha-Beta = 3.54 Sum of Alpha Sum of Alpha-Beta = 8.02 Sum of Alpha Step10: Compare the overall judgements. Obviously, since 8.02 is greater than 3.54, system B is more desirable, and system A is less desirable. Also, from the Beta scale, we can draw the conclusion that system A is undesirable with respect to the objectives as a whole while system B is preferable. Notice that system B has emerged as a better solution even though it scores badly in relation to short erection time (02). Such a decision is quite possible if the objectives have been ranked and weighted accurately enough to represent the 132 decision-maker's values. Nevertheless, if the result seems intuitively unacceptable to the decision-maker, it is suggested that the ranks and weights of the objectives should be reexamined, and the process repeated to check original assumptions. 133 6.1.2 Group Evaluation As on mentioned earlier, no substantial is systems building research basis of a sophisticated the performance so discernible, program and complete prediction on statistical data base in Thailand has not been yet developed practicality at the moment. Thus, this lack to the point of of systemic performance prediction requires a certain method can offset this weakness. Such a method ought to have which the capacity whatsovever, the of to bringing past experiences, in form any facilitate a more effective management of decision-making process. Rittel's method among step-by-step, Evaluation Procedure 2) others. hopefully, which, 1: described become application. judgement. Each member makes a list of the aspects or parameters that are important Step 3: will a Each member of the group makes an off-hand, overall Step 2: is procedure The self-explanatory, in terms of Step for Groups is such (objectives). Each member weights the objectives to indicate his judgement concerning relative importance among themselves (Alpha values). WAIT ONE TO TWO WEEKS, then repeat steps 1 through 3. Discard the first results and keep 134 the second Step 4: Assemble a union list of aspects/parameters (objectives) made up of all those submitted by all members of the group. Edit the union list to eliminate repetition. Step 5: Distribute the edited union list to all members of the group and ask them to weight the objectives in accordance with their judgements concerning relative importance among themselves (Alpha values). Step 6: Each member of the group scores each alternative (or system) against each objective on the union list Step 7: (Beta values). Overall deliberated scores are computed (Alpha-Beta values). ALL THE GROUP'S DELIBERATIONS UP TO THIS POINT MAY HAVE TAKEN PLACE WITHOUT A FACE-TO-FACE MEETING. Step 8: Compare each individual's off-hand judgement from step 1 with his deliberated judgement from step 7. Step 9: The result of the first eight steps is a deliberated, overall judgement. The role of each individual 135 person in the process may be anonymous up to this point; is desirable, unequal this if the participants are of rank or prestige. A face-to-face meeting might be considered at this stage. One of the functions of such a meeting is to discuss whether the results of step 8 are to stand as the group's decision. 1. A pre-weighting of the aspects can be used to generate the right arguments, and to avoid wasting time on trivial matters. 2. People may arrive at similar overall judgements for quite different reasons. Causes of extreme disagreement can be analyzed and discussed by searching for widely divergent weighting and scoring judgements from steps 5 and 6. 3. The group may decide to deliberate further in areas of major disagreement, perhaps generating research or simulation projects in the process, or to repeat the entire cycle, or to break down some important aspects into sub-aspects and/or to construct more detailed criterion functions. Step 10: Either decide to act upon the deliberated judgement of step 8 or to recycle or revise, as described in step 9. 136 6.2 SYSTEMS SELECTION AND ASSESSMENT all acquiring After that the methods and information to essential for the application of a systems approach are total process needs to be integrated into the building, a coherent whole. However, in terms of the efficacy of systems the last step, i.e., approach, of perhaps, the most important part is, systems, the selection and evaluation of the approach, since value is what we are aiming at from the very beginning. It is a strategic point, where various factors or the process are made to interact in components each with other. capacity certain of effort this all of answer considering context it should be noted that it is beyond again, Once vast the the problems stated of defined scope precise a to determine or and/or earlier, less be shown is mainly intended for illustration purposes, it may certain in a real situation to a and defined variables. The selection and evaluation process be useful the to and point. However, it is strongly recommended that attention should be paid mostly than to process to how the procedure can be the rather end result presented here. than product regardless. 137 is of utilized, rather other words, In utmost concern, 6.2.1 Alternatives the of 2 step to According alternatives to be evaluated have to be chosen. one, of construction systems with concerned second In our case, (Chap.4). aspects planning (Chap.3) For is one two dimensions of alternatives, the first have we method, selection the and first the construction are comprised dimension, alternative systems of of: 1) Conventional 2) Small System, Component System, 3) Prefabricated Post & Beam System, and 4) Prefabricated Panel In and a terms new System. of planning, a conventional proposed plan applying by plan of the SAR NHA methodology (Chap.4,4.4) are used two plan options. Therefore, options we want to test all dimensions of the against the selection criteria, the following eight alternatives A-1 if (see Fig. 6.3) will Conventional be judged in the process: plan, conventional system of construction component system A-2 Conventional plan, small A-3 Conventional plan, prefabricated post&beam system A-4 Conventional plan, prefabricated panel 138 system system of construction A-5 Support plan, conventional A-6 Support plan, small component system A-7 Support plan, prefabricated post&beam system A-8 Support plan, prefabricated panel 139 system A-4 Fig. 140 6.3 6.2.2 Weighting Criteria Weighting the selection criteria or objectives, using (The "ties-allowed" rules the Method of Paired Comparisons will apply, with 1/2 given to both objectives) Ca c -4q 0 1 CVIMiLn 0 _ 01 i 0 -4 r- (r1I j- LA rV"r-i I "' I'-I! 1 1 1 03 0 0 - 1 1 1 11 1 0 1 . 0 0 2 0 0 0 10 0 0000000000000000000000g000301 04E0o02 0 10 h 0 0 1 1 1 h 1 2 1 0 0 0 n1 1 o 0 13117 0 0 0 1 1 h 3 21 1 1 h1 1 010 0 0 0 0 0 0 28 3.5 13 10 10 h 10 0 0X h h ;-2 1 hXh0 0010100 15 h 11 h kX 11 00 19 1 25E3n_0n11000 E6 1 1 1h 11 h 0 16 10 10 k 0 00 0 10 h 0 0 2 0 17 0 0 EX2 1 0 010 0 h 28 (N (N 00 - (A 3.9 4.8 0.8 0.2 h 14 10 1 C4 CNI 0 0 C0 (NI 0001912.5 2.9 h 0 0 0 11 1 1 h 0 0 1 05 0 01 1 3.5 0 0 0 17 15 1 1 h 0 01 h h h 1. . 11 1 J- 0 0 1 3.7 016 16 1 Xh 21n I -2 hk0 h -2 1 E710 -2_LO 3.9 13 17 11h 1 . 00 01 1 1 1 1 h 1 1 0 08 h I 0 23 11.5 2. oo0 1 1 nn 0o H 0 0 0 110 0 1 1 1 1 09 _LE k11 h 1 10 10 010111 17.5 4.0 0 1k 12hooj 1111 11 h 1 1 1 n 1h n3n 0919 4.4 06 010 1 1 18 '-0 O4 uL 0 h00 1 1 0 0 h I k 0 o 1 1 11 h 1 20 E 11111nk 1 X 010 0 0 0 0 0 0 1 h 1 nh-- 1 11 12nXhXk 19 12.5 17 17.5 k 1 110 Ih 0 0 13 1n2 1 1 h XX0011 2 1 1 26 5.5 0 0 0 22 12 0__002655 . 0__ 1 1 11 1 1 1 21 E 1 1 1 2 3 21 2 321 21 0 0 Eh. 0n 0 0 0 0 0 0 0 0.0 0 0 0 0 0 X 0 0 0 0 0 0129 3 1 1 h 0 1 1 1 X 0 0 18 14 h0 22 0 0 1 h 0 1 h001 1 0000019 12.5 23 0 E 1 1 24E h 1 1 h 0 0 0 0 0 0 00 10 10 0 0 h 0 0 00 0 0 0 25 6 249 X 000 10h110 10 00 is1h M koh 11 h k h110 1 h 1 1 2 h 1no 1 n n X 11 h ho 1 1 1 1 Xn-n XX 620.5 XXXh E7 1n 1 1 11 7 20 12 1 1 1-2 0 1 01.s 1n 11 24 3 2.9 3.9 4.0 1.3 2.8 4.8 4.8 0.7 3.2 2.9 1.4 2.1 4.3 4.7 4.6 5.5 Alpha Total loo 141 Scale: Selection Criteria in Ordinal 0-29 Living units should be expandable 0-30 Living units should be rearrangeable 0-2 Minimize cost of construction & maintainance 0-19 Maximize use of available technical know-how and technicians 0-20 Develop management and technical existing capacity of technicians 0-27 Short term returns of investment 0-12 Minimize imported materials 0-28 Minimize erection time 0-11 Maximize consumption of locally produced materials or products 0-26 Minimize initial capital investment in construction 0-10 Maximize the use of local craftsmanship 0-15 Maximize interchangeability of components, available in the market 0-1 Improve the performance of buildings and subsystems 0-8 Simple on-site assembly 0-14 Minimize consumption of wood (includ. formwork, scaffolding) 0-7 Minimize use of skilled workers 0-6 Short "learning curve" 0-22 Minimize technical support from other agencies 142 0-5 Maximize unskilled labor 0-13 Reinforced concrete is desirable 0-23 Minimize highly sophisticated management, but improve to achieve higher attainable level of sophistication 0-17 Post & beam method is preferrable 0-9 Minimize finishing on site 0-25 Road transportation: medium to light-weight equipment and vehicles 0-24 Handling off site: manual and medium to light-weight machinery 0-16 Minimize idle material stock and waste on sit e 0-18 Handling on site: manual and medium to light-weight machinery 0-3 Number of units to be built: 5,000-6,000 unit s 0-21 Endure discontinuous product line housing policy) 0-4 Unit height: 5 stories 143 (inconsiste nt 6.2.3 Systems Judgement By means of Beta the Alpha-Beta Model, with scales: 9 = Excellent satisfaction 4 = Poor satisfaction 8 = Good satisfaction 3 = No satisfaction 7 = Average satisfaction 2 = Very unsatisfactory 6 = Moderate satisfaction 1 = Totally incompatible 5 = Indifferent satisfaction The aggregation form = Sum of Alpha-Beta Sum of Alpha 144 Table 6.4: Objectives a-value 0-29 0-30 0-2 0-19 0-20 0-27 0-12 0-28 0-11 0-26 0-10 0-15 0-1 0-8 0-14 0-7 0-6 0-22 0-5 0-13 0-23 0-17 0-9 0-25 0-24 0-16 0-18 0-3 0-21 0-4 Sum Al The Alpha-Beta Model A2 A3 5.5 5.5 4.8 4.8 4.8 4.7 4.6 4.6 4.4 4.3 4.0 4.0 3.9 3.9 3.9 3.7 3.5 3.2 2.9 2.9 2.9 2.8 2.6 2.1 1.4 1.3 1.3 0.8 0.7 0.2 100.0 145 Beta value A5 A4 A6 A7 A8 Table 6.5: The Alpha-Beta Model(showing Alpha-Beta Product) Qbjectives a-value Al A2 Alpha-Beta product A7 A6 A5 A4 A3 0-29 0-30 0-2 0-19 0-20 0-27 0-12 0-28 0-11 0-26 0-10 0-15 0-1 0-8 0-14 0-7 0-6 0-22 0-5 0-13 0-23 0-17 0-9 0-25 0-24 0-16 0-18 0-3 0-21 0-4 33 27.5 28.8 14.4 14.4 37.6 41.4 27.6 39.6 38.7 36 20 3.9 11.7 11.7 11.1 31.5 25.6 20.3 23.2 23.2 25.2 13 16.8 11.2 3.9 10.4 4 5.6 1 5.5 27.5 33.6 28.8 28.8 37.6 36.8 36.8 35.2 34.4 32 32 31.2 23.4 27.3 18.5 24.5 22.4 23.2 23.2 20.3 14 18.2 16.8 11.2 7.8 10.4 4 5.6 0.8 22 27.5 38.4 38.4 33.6 32.9 32.2 41.4 35.2 30.1 32 36 31.2 27.3 27.3 25.9 28 19.2 23.2 23.2 23.2 25.2 20.8 16.8 11.2 9.1 10.4 4.8 4.9 1 Sum 5.5 5.5 4.8 4.8 4.8 B 4.7 4.6 4.6 4.4 4.3 4.0 4.0 3.9 3.9 3.9 3.7 3.5 3.2 2.9 2.9 2.9 2.8 2.6 2.1 1.4 1.3 1.3 0.8 0.7 0.2 5.5 27.5 43.2 28.8 38.4 18.8 27.6 32.2 30.8 21.5 16 20 35.1 31.2 35.1 29.6 14 9.6 11.6 23.2 11.6 8.4 23.4 6.3 4.2 10.4 3.9 5.6 2.1 0.8 49.5 44 24 14.4 14.4 37.6 41.4 23 39.6 34.4 32 20 7.8 11.7 11.7 11.1 31.5 25.6 17.4 23.2 20.3 25.2 13 16.8 11.2 3.9 10.4 4 5.6 1 49.5 44 28.8 28.8 28.8 37.6 36.8 32.2 35.2 30.1 28 32 31.2 23.4 27.3 18.5 24.5 22.4 20.3 23.2 17.4 14 18.2 16.8 11.2 7.8 10.4 4 5.6 0.8 100.0 Sum of Alpha-Beta Product: Al = 612.3 A2 = 671.8 A3 = 732.4 A4 = 576.4 A5 = 625.7 A6 = 708.8 A7 = 757.2 AB = 613.4 By using the aggregate form = Sum of Alpha-Beta Sum of Alpha 146 49.5 44 33.6 38.4 33.6 32.9 32.2 36.8 35.2 30.1 28 36 31.2 27.3 27.3 25.9 28 19.2 20.3 23.2 20.3 25.2 20.8 16.8 11.2 9.1 10.4 4.8 4.9 1 AS 49.5 44 38.4 28.8 38.4 18.8 27.6 27.6 30.8 17.2 12 20 35.1 31.2 35.1 29.6 14 9.6 8.7 23.2 8.7 8.4 23.4 6.3 4.2 10.4 3.9 5.6 2.1 0.8 scores 612.3 = 6.12 100 A5 scores 625.7 = 6.26 100 A2 scores 671.8 = 6.72 100 A6 scores 708.8 = 7.09 100 A3 scores 732.4 = 7.32 100 A7 scores 757.2 = 7.57 100 A4 scores 576.4 = 5.76 100 AS scores 613.4 = 6.13 100 Al 147 7.3.5 Systems Assessment terms of In favor of post high the beam system is system. The desirable most relatively defined context, since it scores the system in almost every objective. The areas where the performs know-how, the & outstandingly the system, component small system, and the prefabricated panel prefabricated vis-a-vis the by consecutively followed system, prefabricated post & beam the conventional construction, the evaluation is clearly in technical are the use of available the interchangeability of components available in finishes market, the minimization of erection time and on-site. Moreover, the post & beam method of construction is generally fact acceptable to local craftsmen. Another important is that the sizes of the components within the system present no difficulties in transportation, handling on-site, as well as, off-site. Considering the evaluation score, the system is on the scale of average to good satisfaction. The component or partial small prefabricated also scores relatively high, in general. much However, system it is very inferior in certain areas such as the minimization of improvement of skilled on-site labor, technicians' capacity. assembly, The system, and it since is a wall-bearing type, is less desirable, compared to any post & beam system. satisfaction As a whole, it scores on the beta scales. 148 moderate to average The least conventional desirable system has turned out not to be system, since most of moderate satisfaction. well in many areas, context, such as know-how, the technicians' Nevertheless, it does especially the the potential improvement capacity, its score is of the of around not areas of existing existing the respond changing technical standard consumption of wood, and the scarcity of skilled workers. The problems on-site, i.e., handling time),, the of materials, the assembly process (long of the erection and the problem of finishes, are also weak points of system. On the beta scales, moderate satisfaction is performance of where the system performs. On the average, prefabricated panel of the overall method is approximately the same as that conventional systems, which should not be the case. point is, while the system responds quite well area, it good performs very badly in another; in terms building performs wood badly investment simple and consumption, areas of return, the utilization interchangeability, better maintainance skilled and on-site the capital and in a certain while it is assembly, in maximization. entails construction performance, requirement, component of of The very cost, labor finishes, investment local unskilled it and craftsmen, labor Furthermore, the implementation of the system management and 149 solid technical research Transportation equipment situation As support and in the conventional not moment. the handling, which require in compliance the with heavy current Thailand. regards plan at both not available material also are construction process, are which background planning, should be it noted is always more desirable when one is considered support plan one in terms of at a time. In definitely the 150 system the of evaluation outperforms flexibility and as stated in the objectives. that the extensibility CONCLUSIONS & RECOMMENDATIONS recent decades, one of the most In important tasks of the is to provide decent housing for developing countries increasing number of people with their dwindling resources. Accordingly, various building systems have been invented and introduced (initially transfered to systematizing in the western hemisphere and developing for countries) the later sake of the design, planning and production processes of construction industry. Each building system is responding to a certain set of pressing demands for the optimization of of aspects various Therefore, resources. panacea quality, that time, cost, be applied wherever can is system as such building available and regardless not of a the environment. the light of the above, there is an urgent need for In a method to justify various building systems vis-a-vis context. A method is needed to rank the alternate differing building schemes by evaluating their overall desirability as their regards anticipated subjected in real system the context and environmental factors to which they would variables In performance under be use. order to evaluate and select any desirable building in guidelines a are given context in a systemic necessary. First of all, 151 way, certain the objectives of the base followed by have to be made clear, project line and analysis which mainly involve the context data gathe ring such as land, labor, management, etc. Performance variables of the desired building system or scheme has to be criteria developed. From the aforementioned procedures, criteria objectives can be alternativ e or schemes and evaluation step next The scheme. desirable for established systems. is of selection the the of stage of take selection of alternatives can place, value phas e consists of three basic components, i.e., this and decision-maker the priorities attached the of aims to articulate the objectives which component a generation the Finally, or to those objectives, performance component which represents a process which to helps decision predict the building and performance, component which represents a process which help to determine the desirable building schemes. However, the area where most technicians always fail to address is the real user needs and requirements. The housing demand cannot be viewed just in terms of quantity and economy, quality should be taken into consideration as well. A new possibility of using qualitative criteria for building performance should also be initiated in housing design and construction. With the help of building performance concept, user which feedback would can be formalized into performance mediate user requirements environment. 152 and criteria the built In the final analysis, this study has, above all, pointed out the need for further work towards: 1) Development of a comprehensive set of performance prediction models along with supporting data banks for the evaluation of building performance. 2) Evaluation of the performance of building in use and making its comparison with the evaluation of anticipated performance of a scheme during the design development phase. 3) Development of extensively acceptable criteria, measures and performance requirements in other dimensions such as the perceptual aesthetic and sociological contexts to a comparable degree of refinement as in the technological and economic contexts. 4) Development of more specific bases for the establishment of context, criteria, and measure weightages. 5) Investigation into the time characteristics of the value system as represented by the relative weightages of various selection criteria (If the designer has some rational basis for predicting the value system under which his building will will function in future, he be best served in the decision process). 153 REFERENCES INTRODUCTION 1) Manoharn, S., "Improving the Production Process of the Housing Industry in Thailand," Report, Bartlett School of Architecture and Planning, University College London, 1978, p.1. Chapter 1. 1) Wang, C.C., "Observations from 181 Surveys of Urban Dwelling Environments in Developing Countries," Master Thesis, Massachusettes Institue of Technology, Cambridge, Massachusetts, 1982, p.46. 2) United Nations, "Organization, Management and Supervision of Public Enterprises in Developing Countries," New York, 1974, p.157. 3) Thai News, Office of the Information Attache, The Royal Thai Embassy, Washington D.C., 1982 4) "Thai Labor Abroad," Thai p. 4 8 . Contractors News, May 1983, 5) Wanzel, G., "The Housing Crisis: Is Industrialization the Solution?" IF, vol. 4, no. 3, 1973, p. 3 3 . 6) Wadhwa, L. C., "The Opportunity for Systems Building in Developing Countries," Master Thesis, Asian Institue of Technology, Bangkok, Thailand, 1972, p.76-78. 7) Manoharn, S.,, "Improving the Production Process of the Housing Industry in Thailand," Report, Bartlett School of Architecture and Planning, University College London, 1978, p. 2 7 - 2 8 . 8) Ibid. p.29-31. Ounnapiruk, K., "The Evolution of Construction Materials in Thailand," Master Thesis, Chulalongkorn Universit;y, Bangkok, Thailand, 1976. Huntrakul, K., "Study and Survey of Available Construction Materials, Equipment and Labor in Thailand," Thesis No. 804, Asian Institue of Technology, Bangkok, Thailand, 1975. Chiradamkerng. W.., "Industry of Precast Concrete Floor Elements in the Bangkok Area, " Thesis No.-, Asian Institue of Technology, Bangkok, Thailand, 1982. 154 9) Manoharn, S., "Improving the Production Process of the Housing Industry in Thailand," Report, Bartlett School of Architecture and Planning, University College London, 1978, p.21- 2 4 . 10) Rerkshanandana, N.., "Prefabrication in Housing Construction," Thesis No. 688, Asian Institue of Technology, Bangkok, Thailand, 1974 Manoharn, S.., "Improving the Production Process of the Housing Industry in Thailand," Report, Bartlett School of Architecture and Planning, University College London, 1978, p. 2 7 - 2 8 . Moavenzadeh, F., "Choice of Appropriate Technologies in the Housing Sector for Conditions Prevailing in Developing Countries," presented to The International Conference on Housing Planning, Financing in Construction, December 2-7, 1979, Miami Beach, Florida. 11) Huntrakul, K., "Study and Survey of Available Construction Materials, Equipment and Labor in Thailand," Thesis No. 804, Asian Institue of Technology, Bangkok, Thailand, 1975. 12) Manoharn, S., "Improving the Production Process of the Housing Industry in Thailand," Report, Bartlett School of Architecture and Planning, University College London, 1978, p. 2 7 - 2 8 . 13) Building Systems Development Inc., "The Potential for System Building," prepared for the Post Office 7 Department, Washington, D.C., 1969, p. . Chapter 2. 1) Ocharoen, U., "Urban Dwelling Environments, Bangkok, Thailand; Case Studies - Klong Toey Urbaniztion Project," Master Thesis, Massachusetts Institue of Technology, Cambridge, Massachusetts, 1974. Chapter 3. 1) Research and Construction Department, NHA, "NHA Housing Pototypes 1973-1981," August, 1981. 2) Sridurongkatum S., "A Study of Construction Methods of Low-Income Multi-Family Housing, " Thesis No. 1335, Asian Institue of Technology, Bangkok, Thailand, 1978. Chapter 4. 1) N.J.Habraken, "Three R for Housing," 155 Scheltema & Holkema, Amsterdam, 1970. Habraken, N. J.; Boekholt, J. T.; Dinjens, P. J. and Thijssen A. P., " Variations: The Systematic Design of Supports", MIT Press, Cambridge, Massachusetts, 1981, p.45. Chapter 5. 2) M.; 1) Cronberg, T., "Performance Requirements for Buildings - A study based on user activities,"Swedish Council for Building Research, Stockholm, 1975, p.9. 2) Wright, J.R., "The Performance Approach: History and Status," Performance Concept in Buildings, NBS Special Publication 361, vol. 2, Washington, D.C., 85 0 . u.S. Government Printing Office, 1972, p. 3) Voilett, J., "The Relationship between the Performance Concept and the Systems Concept," Performance Concept in Buildings, NBS Special Publication 361, vol. 1, Washington, D.C., u.S. 2 11 . Government Printing Office, 1972, p. 4) Cronberg, T., "Performance Requirements for Buildings - A study based on user activities,"Swedish Council 3 1 . for Building Research, Stockholm, 1975, p. 5) Ibid. p.46. Chapter 6. 1) Grant, D.P., "How to Use an Alpha-Beta Model for Decision-Making with Multiple Objectives," DMG-DRS Journal, vol. 10, no. 4, Oct.-Dec. 1976. 2) Ibid. 156 SELECTED BIBLIOGRAPHY Bender, "Selected Technological Aspects of the American R., Building Industry," (A report prepared for the National Commission on Urban Problems), New York. "The Systems Approach to Building, A Core of Brandle, K., Information," ACSA Learning Package, Graduate School of Architecture, University of Utah, 1976. Building Systems Development Inc., "The Potential for System Building," prepared for the Post Office Department, Washington, D.C., Information Business 1969. ltd., and Research co. "Thailand Camous, R., "The Performance Concept New Building Products," p. 5-10. 1982", 1981. United Production, Bangkok, Thailand, and the Evaluation of IF vol. 3, no. 3, Feb. 1972, Chiradamkerng. W., "Industry of Precast Concrete Floor Elements in the Bangkok Area, " Thesis No.-, Asian Institue of Technology, Bangkok, Thailand, 1982. "Performance Requirements for Buildings - A Cronberg, T., study based on user activities,"Swedish Council for Building Research, Stockholm, 1975. Dluhosch, E., vol. "Flexibility/Variability and Programming," 5, no. 5, 1974, p. IF, 39-45. Ehrenkrantz, E.D., "The system to systems," 1970, p. 56-59. X_ AIA Journal, May Goodmam, L. J.; Pama, R. P.; Tabujara, E. G.; Razani, R.; Burian, J.; "Low Cost Housing Technology -An East-West Perspective," Pergamon Press, New York, 1979. Grant, D.P., "How to Use an Alpha-Beta Model for Decision-Making with Multiple Objectives," Journal, vol. 10, no. 4, Oct.-Dec. 1976. Grant, D.P., "How to Use the Method of Paired DMG-DRS Comparison: A Systematic Approach to the Task of Ranking Things," DMG-DRS Journal, vol. "Three R for Habraken, N. J., Amsterdam, 1970. Habraken, N. J.; Boekholt, J. 10, no. 4, Housing," T.; 157 Oct.-Dec. 1976. Scheltema & Dinjens, P. J. M.; Holkema, and Thijssen A. P., " Variations: The Systematic Design of Supports", MIT Press, Cambridge, Massachusetts, 1981. Huntrakul, K., "Study and Survey of Available Construction Materials, Equipment and Labor in Thailand," Thesis No. 804, Asian Institue of Technology, Bangkok, Thailand, 1975. Kadri, T.E., "Guidelines for the Evaluation of Building Systems in the United Arab Emirates," Master Thesis, Massachusetts Institue of Technology, Cambridge, Massachusetts, 1982. Kiatfuengfoo, V., !A Site and Services Model, Bangkok, Thailand," Master Thesis, Massachusetts Institue of Technology, Cambridge, Massachusetts, 1981. Moavenzadeh, F., "Choice of Appropriate Technologies in the Housing Sector for Conditions Prevailing in Developing Countries," presented to The International Conference on Housing Planning, Financing in Construction, December 2-7, 1979, Miami Beach, Florida. Manoharn, S., "Improving the Production Process of the Housing Industry in Thailand," Report, Bartlett College, London, 1978. Narumit, S.., "Development of Infrastructure of Industrialized Housing in Thailand," in Southeast Asian Low-Cost Housing Study, Thailand Country Monograph, presented to the Low-Cost Housing Conference in Penang, April 15-19, 1974, 8 p.p. National Identity Board, "Thailand 1982 - Plan, Problems and Prospects," Graphic Art Publishing, Bangkok, Thailand, 1982. National Statistical Office, "Statistical Yearbook, Thailand," no. 31, 1974-1975, Office of the Prime Minister, 1976. Ocharoen, U., "Urban Dwelling Environments, Bangkok, Thailand; Case Studies - Klong Toey Urbaniztion Project," Master Thesis, Massachusetts Institue of Technology, Cambridge, Massachusetts, 1974. Ounnapiruk, K., "The Evolution of Construction Materials in Thailand," Master Thesis, Chulalongkorn Universit;y, Bangkok, Thailand, 1976. Pama, R.P., Angel. S., and De Goede, J. 158 H., "Low-Income Housing-Technology and Policy," Proceedings of the International Conference on Low-Income Housing-Technology and Policy, Asian Institue of Technology, Bangkok, Thailand, 1977. Rerkshanandana, N., "Prefabrication in Housing Construction," Thesis No. 688, Asian Institue of Technology, Bangkok, Thailand, 1974 Sakr, S., "In-Use Modification of Existing Public Housing in Cairo, Egypt," Master Thesis, Massachusettes Institue of Technology, Cambridge, Massachusetts, 1983. Sridurongkatum S., "A Study of Construction Methods of Low-Income Multi-Family Housing, " Thesis No. 1335, Asian Institue of Technology, Bangkok, Thailand, 1978. "A Systemic Process for Management Level Smothers, F.T., Between Alternative Organizational Structures for the Planning, Production and Operation of Constructed Facilities," DMG-DRS Journal, vol. 9, no. 2, April-June 1975. U.S. Department of Commerce/National Bureau of Standards, "Performance Concept in Buildings," NBS Special Publication 361, vol. 1, Washington, D.C., U.S. Government Printing Office, 1972. United Nations, "Organization, Management and Supervision of Public Enterprises in Developing Countries," New York, 1974. Thai Contractors News, Bangkok, May 1983. The Office of the Prime Minister, "Thailand - into the 80's," Thai Watana Panich Press, Bangkok, Thailand, 1979. Van Huyck, A. P., "Review of the Policies, Programs and strategies of the National Housing Authority of Thailand," prepared for the Office of Housing Agency for International Development, Washington, D.C., 1976. Voilett, J., "The Relationship between the Performance Concept and the Systems Concept," Performance Concept in Buildings, NBS Special Publication 361, vol. 1, Washington, D.C., u.S. Government Printing Office, 1972. Wadwa, L.C., "The Opportunity for Systems Building in Developing Countries," Thesis No. 470, Asian Institue 159 of Technology, Bangkok, Wang, Thailand, 1972. C.C., "Observations from 181 Surveys of Urban Dwelling Environments in Developing Countries," Master Thesis, Massachusettes Institue of Technology, Cambridge, Massachusetts, 1982. Wanzel, G., Is "The Housing Crisis: Solution?" IF, vol. 4, no. 3, Industrialization the 1973, p. 29-36. Ware, T.E., "Performance Specifications for Office Space Interiors," Performance Concept in Buildings, NBS Special Publication 361, u.S. Government Wright, vol. 1, Washington, D.C., Printing Office, 1972. The Performance Approach: History and Performance Concept in Buildings, NBS J. R., Status," " Special Publication 361, vol. 2, u.S. Government Printing Office, 160 Washington, D.C., 1972.