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,"
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Cambridge, Massachusetts, 1982, p.46.
2) United Nations, "Organization, Management and
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3)
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4)
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8)
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154
9)
Manoharn, S., "Improving the Production Process of
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Manoharn, S.., "Improving the Production Process of
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11)
Huntrakul, K., "Study and Survey of Available
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13) Building Systems Development Inc., "The Potential for
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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 &
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1970.
Habraken, N. J.; Boekholt, J. T.; Dinjens, P. J.
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Chapter 5.
2)
M.;
1) Cronberg, T., "Performance Requirements for Buildings
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for Building Research, Stockholm, 1975, p.9.
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2)
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156
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