CEST2007 – Cos island, Greece
Ref no: 262/27-12-06
CONSTRUCTION AND DEMOLITION WASTE MANAGEMENT: STATE OF THE
ART TRENDS
N. MOUSSIOPOULOS1, A. PAPADOPOULOS1, E. IAKOVOU2, H. ACHILLAS1,
D. AIDONIS2, D. ANASTASELOS1 and G. BANIAS1
1
Laboratory of Heat Transfer and Environmental Engineering, Aristotle University of
Thessaloniki, Box 483, 54124 Thessaloniki, Greece, 2 Laboratory of Quantitative
Analysis, Logistics and Supply Chain Management, Aristotle University of Thessaloniki,
54124 Thessaloniki, Greece
e-mail: moussio@eng.auth.gr
EXTENDED ABSTRACT
The construction industry has emerged as a crucial sector of the economy worldwide, in
terms of technological, economical and environmental concerns. Especially, regarding
the environmental aspects, the construction industry has proven as one of the key culprit
sectors, both for the consumption of natural resources, as well as for the release of
pollutants to the natural environment. The problem is widespread throughout the world,
with Construction and Demolition (C&D) waste accounting to an estimated 30 - 35% of
the overall municipal solid waste (MSW) stream.
Following the modern trends in the field of C&D waste management, a research team has
been formed in the framework of the research project “Information System for Demolition
Waste Management” (DEWAM project), which is funded by the General Secretariat for
Research and Technology of the Hellenic Ministry of Development. The project aims to
investigate the need for rational changes in the field of C&D waste management in
Greece through the development of an information system. The ultimate objective of the
DEWAM project is to minimise C&D waste that are discarded to landfills without any prior
processing, as well as to increase their recycling and reuse rates.
This paper, apart from a short description of the DEWAM project, focuses on the
presentation of “deconstruction” as a C&D waste management alternative and its
economical and environmental benefits. Laconically, deconstruction is the process of
dismantling buildings, both structural and non-structural components, in order to enable
redundant building materials to be salvaged for reuse and recycling. Although removing
structures as quickly as possible, resulting in limited material salvage, is a standard
demolition practice, deconstruction involves carefully taking apart sections of a building or
removing their contents, with the primary goal to recover the maximum amount of
materials for their highest and optimal reuse and recycling.
Key words: C&D waste, construction and demolition, deconstruction, end-of-life building
materials, reuse, recycling.
1. INTRODUCTION
Construction and Demolition (C&D) waste is generated from the construction, renovation,
repair and demolition of structures such as residential and commercial buildings, roads,
bridges, etc. The composition of C&D waste varies for these different activities and
structures. C&D waste often contains bulky, heavy materials, including concrete, wood
(from buildings), asphalt (from roads and roofing shingles), gypsum (the main component
of drywall), metals, bricks, glass, plastics, salvaged building components (doors,
windows, and plumbing fixtures), trees, stumps, earth and rock from clearing sites. All
these different materials need to be managed in an environmentally sound and economic
feasible manner. Moreover, C&D waste may also contain hazardous materials, such as
asbestos and heavy metals.
The rapid growth of the construction industry worldwide has resulted to an enormous
increase of the produced C&D waste globally. In particular, the C&D waste stream
constitutes the largest stream within the European Union (EU) accounting for more than
450 million tonnes per year. Excluding earth and excavated road material, the amount of
C&D waste generated is estimated to be roughly 180 million tonnes per year [1].
Up to recently, the most common practice in the field of C&D waste management was to
discard all waste materials and debris to sanitary landfills, frequently in the same landfills
that were used for the disposal of municipal solid waste (MSW). This practice cannot in
any case be considered as a proper management practice for end-of-life building
materials. Even worse, there are many cases reported where C&D waste ended up in
uncontrolled open dumps, not taking into account the severe burden imposed upon the
environment. The environmental and health impacts of such disposal and treatment
methods for C&D waste include apart from the aesthetic degradation, soil and water
contamination, air pollution as a result of fires, reduced property values, destruction of
open spaces and landscape blight. In addition, heaps of C&D waste may include
asbestos waste, which poses a significant health risk, especially in building sites which
are transformed into playgrounds and residential buildings.
The aforementioned practice has expanded to all the stages of building materials’
lifecycle: production, construction, use, but most significantly their end of life
management (e.g. demolition of buildings). Further, this practice is closely related to the
popularity of the fact that the majority of existing buildings in modern cities have not been
designed in such a way, so that building materials at the end of their useful life to be
potentially reused or even recycled.
Another major problem in the field is the fact that there are many gaps in literature of
research efforts that could combine environmental, technological and economical aspects
of C&D waste management. Until now, only a few research projects related to C&D waste
management have been undertaken in developed countries (U.S.A., EU, etc.), as well as
sited in scientific literature. Even more, differences in the legislation framework and
variation in construction techniques, work procedures and common practices between
countries, makes it impracticable to directly transfer outcomes and experiences from one
country to another.
Notwithstanding the fact that the current situation in the field does not seem very
optimistic, the underlying dynamics appear to be changing. There are already many
countries that have recognised the problem and the highest importance of
environmentally sound C&D waste management. However, changes still occur in a rather
slow pace.
2. PRESENTATION OF DEWAM PROJECT
In the framework of the Hellenic Programme for the Reinforcement of National Research
Workforce, which is funded by the General Secretariat for Research and Technology of
the Hellenic Ministry of Development, a research team has been formed and has
achieved to qualify for the funding of the project “Information System for Demolition
Waste Management” (DEWAM project). DEWAM’s principle objective is to minimise the
waste of building materials that are discarded to landfills without any prior processing and
to increase their recycling and reuse rates. Through the web portal that will be developed
within the project bounds, the end-user will be able to be informed regarding: (a)
Information on building materials, (b) guidelines for the optimisation of the demolition
procedure and the separation of building materials, (c) recyclable and reusable building
materials, (d) 3rd party logistics companies for the transport and storage of C&D waste,
(e) demolition waste management costs.
For the project needs, two laboratories from the Mechanical Engineering Department of
Aristotle University Thessaloniki (Laboratory of Heat Transfer and Environmental
Engineering and Laboratory of Quantitative Analysis, Logistics and Supply Chain
Management) have been collaborating together with FIBRAN S.A., one of the leading
producers of building materials with domestic and international activity. The user
community of the platform envisaged, consists of building material companies, recyclers,
construction companies, 3rd party logistics (3PL) companies, city authorities, as well as
individuals.
3. CURRENT SITUATION IN THE FIELD OF C&D WASTE MANAGEMENT
Due to the environmental problem raised by the current management of C&D waste
stream, EU has adopted a number of Directives aimed at harmonising waste disposal
policies while guaranteeing environmental protection. The EU regulation of C&D waste
falls under the broader category of waste and is integrated into the broader targets set by
legislation in this area of concern. EU Member States were obligated to adopt the original
waste Directive 75/442/EEC and all further amendments to this law. In September 2005,
the European Commission proposed an overhaul of the 1975 Directive, mostly in order to
lay down rules on recycling and to require Member States to draw up binding national
Programmes for cutting waste production. Lately, Directive 2006/12/EC consolidated and
replaced Directive 75/442/EEC on waste. In 2000, EU with Commission Decision
2000/532/EC introduced the European Waste Catalogue, which came into force on 1
January 2002. Until now, the Catalogue has been amended with Commission Decision
2001/118/EC, Commission Decision 2001/119/EC and Council Decision 2001/573/EC.
In Greece, very recently (7.5.2007), a draft version of the Presidential Decree for the
alternative management of C&D waste has been signed and published [2]. In short, the
Decree sets the approval criteria for C&D waste management plans, organises the
collection, transportation, re-use and recycling of C&D waste and defines the obligations
and responsibilities of C&D waste management companies. In addition, the Decree fulfils
the quantitative targets for the recovery and recycle of C&D waste in Greece, as follows:
 Until 1.1.2010, at least 30% per weight of the C&D waste generated is re-used, from
which at least 50% is recycled.
 Until 1.1.2015, at least 60% per weight of the C&D waste generated is re-used, from
which at least 50% is recycled.
Although in many countries all over the world C&D waste has been identified as a “priority
waste stream” which resulted to a number of regulations that have been adopted relating
to the management, transport, treatment and disposal of this particular type of waste,
there are still many countries that have fell behind in the field and C&D waste
management has unfortunately not been covered by certain regulations. It is obvious that
in the latter countries, legislation regarding C&D waste needs to move ahead
aggressively and the responsible parties should be decisive by implementing specific
policies and measures requiring the reuse of recycled C&D waste.
4. ALTERNATIVES AND MODERN TRENDS IN C&D WASTE MANAGEMENT
The primary goal of the proper C&D waste management is to divert the maximum amount
of building materials from the waste stream. High priority is placed on the direct reuse of
materials, either in new or existing structures. Immediate reuse allows the materials to
retain their current economic value. Materials that are suitable for immediate reuse can
be recycled, downcycled (reuse on a lower level) or upcycled (creation of value added
products and provision of quality materials to new businesses and manufacturers) [3].
Upcycle
WASTE
MANAGEMENT
HIERARCHY
REDUCE
REUSE
RECYCLE
Deconstruction
Downcycle
LANDFILL
Figure 1: Waste Management Hierarchy
The waste hierarchy, as this is shown in Figure 1, suggests that the most effective
environmental solution is the reduction of the waste generation. The reduction of waste
minimises total management cost, reduces pollution from the stages of manufacturing
and transportation and saves energy and water, while keeping waste out of landfills.
Waste reduction should be the first priority in C&D waste management plans. For the
cases that further reduction is not feasible, products and materials can often be reused,
either for the same or for a different purpose. Reusing of obsolete building materials
extends their life cycle and therefore decreases the need for new resources. Entire
buildings can be reused through renovation, either for the same or even for a different
use, saving both resources and capital. In practice, the reuse or salvage of building
components in renovations is being mostly extended to non-decorative elements, such as
doors and light fixtures. This approach can be pushed even further under the assumption
that new elements do not always perform better than old ones. Failing that, value should
be recovered from waste through recycling, composting or energy recovery from waste.
Recycling conserves resources and diverts materials from landfills. Demolition and
renovation projects present numerous opportunities for recycling. The most sustainable
form of recycling converts waste into new products, such as scrap to new steel or asphalt
into new paving. Additionally, finding alternative uses for waste is another form of
recycling. Inert waste, such as concrete and brick, can be crushed and used as
alternative daily cover for municipal landfills. Only in the few cases that none of the
aforementioned solutions are appropriate should waste be disposed of in sanitary
landfills.
The total economic and environmental impact of the construction industry – supply / value
chain begins with raw material extraction and continues with products’ manufacturing and
transportation, building design, construction, operation, maintenance, and end-of-life
management. Extraction of natural resources, especially through mining and smelting, is
one of the most wasteful, energy intensive and polluting industries globally. Every single
building component contains vast quantities of embodied energy. Reusing and recycling
building materials prevents environmental impacts by reducing the need for virgin natural
resources to be mined and harvested, while saving forests and natural areas from further
degradation [4].
Lately, along the lines of international initiatives towards sustainability, several changes
have occurred in the construction industry. In brief, there has been a shift towards using
environmental friendly materials, more energy efficient structures, the proper
management of C&D waste, as well as the implementation of reuse and deconstruction.
The current practices for the C&D waste management are described in the paragraphs
below:
Landfilling: The current practice of C&D waste management is the disposal of materials
to landfills or in uncontrolled dumps. Landfills have limited space and therefore can only
receive a limited amount of waste. When one landfill reaches its maximum capacity, it
needs to be replaced by another one, which in most cases is more expensive to operate
and maintain. The higher cost is a result of complying with environmental regulations,
buying or allocating land, constructing the landfill, operating expenses, as well as long
term maintenance costs after the landfill is closed. Additionally, as cities expand, the new
landfill would probably be built farther away, thus increasing transportation costs. The
higher cost of constructing a new landfill is avoided by keeping the old one active.
Therefore, keeping existing landfills operating as long as possible is beneficial not only to
the environment, but also to the local community, which is paying for waste management
through tipping fees or taxes [3].
Demolition: The demolition industry has undergone a major transformation within the
last 20 years. Traditionally, it has been a low-skill, low-technology, and poorly regulated
industry, dealing mainly with the disassembly of simply constructed buildings. During the
last few years, following the trend of all major industry sectors, it has been automated,
replacing workers with machines. Recently, the demolition industry employs fewer but
more highly skilled operators, as well as very expensive highly dedicated equipment. In
brief, there is a wide variety of demolition techniques, both regarding their practices, as
well as their technology, application, cost and speed. Traditional methods, such as the
steel ball, are being rapidly replaced by more modern methods, as the emphasis migrates
from masonry and brickwork to concrete and steel structures.
According to Kasai et al [5] there are eight factors, which affect the choice of demolition
methodology. Every building will be subject to a unique combination of those factors:
i) Structural form of the building regarding the technology and materials involved in its
construction.
ii) Scale of construction, since a large-scaled building may make a complex method
economically viable, while a small-scaled building could be preferably demolished by
hand.
iii) Location of the building, since access can affect the choice of preferable equipment.
iv) Permitted levels of nuisance, since noise, dust and vibration tolerances vary heavily
on the structure’s individual characteristics.
v) Scope of the demolition, since some methods are not suitable for partial demolition.
vi) Use of the building, since a contaminated structure will be treated differently to an
ordinary residential terrace.
vii) Operative and environmental safety.
viii) Time availability.
The first six factors are related to the physical aspects of the building to be demolished,
while the last two are an indication that the characteristics of the building are not the sole
consideration when deciding on a particular demolition methodology. The inclusion of the
time factor demonstrates that the contractual conditions can have a significant effect on
choice, whilst the inclusion of safety aspects points out the influence of issues such as
legislation and environmental protection.
The demolition process relies on one of eight basic methods; pulling, impact, percussion,
abrasion, heating (or freezing), expanding, exploding and bending. Demolition methods
are classified into traditional, explosion and more modern methods. However, in most
cases it is likely that the demolition is a combination of the aforementioned methods [3].
Deconstruction: In brief, deconstruction is the disassembly and recovery of a building in
the reverse order of its construction. The goal of any building deconstruction project is to
maximise the recovery of salvageable material within a reasonable time frame, at the
lowest possible cost. It combines the recovery of both reusable and recyclable materials
with regards to both qualitative and quantitative parameters. The common practice is to
pick or strip out highly accessible recyclable and reusable materials prior to traditional
demolition. Wood flooring, raised panel doors, ornate interior and exterior trim, electrical
and plumbing fixtures, even framing and bricks can have salvage value of up to 75% of
the item’s original value. Traditional demolition usually involves mechanical demolition,
often resulting in a pile of mixed debris, which is often sent to the landfill. Deconstruction
is emerging as an alternative to demolition around the world and has several advantages
over conventional demolition, such as:
 Increased diversion rate of demolition waste from landfills, which extends landfills’
useful life.
 Potential reuse of building components and ease of materials recycling.
 Protection of the natural environment by reducing the need for the extraction of new
resources, while preserving the embodied energy of materials
 Job creation and economic development.
 Supply of useful materials to building materials yards, recycling centres, remanufacturing enterprises.
Research indicates that deconstruction may cost 30 – 50% less than demolition. Since
deconstruction is a more time consuming alternative than demolition, project labor costs
can be significantly higher. However, the higher labor costs are offset by lower equipment
costs. Deconstruction does not require heavy equipment but rather relies primarily on
hand tools and small machinery. Therefore equipment rental costs are lower. Items
removed through deconstruction can be reused in the construction of new developments
or sold to a salvaging company. Research, further shows that the market value for
salvaged material is considerably higher with deconstruction rather than with demolition,
due to the special care taken in removing materials. Revenues from salvaging can be
used to offset other redevelopment costs. In addition, disposal costs (if there are any) are
also lower with deconstruction, as this process reduces the amount of overall waste
produced by up to 75% [6].
Deconstruction requires workers who are trained to extract salvageable materials from
buildings slated for demolition. Training in this process provides new employment
opportunities for a minimally skilled work force. In addition, small businesses could be
created to handle the salvaged material that would enable businesses to link a
deconstruction project to economic development and job training efforts.
The environmental benefits of deconstruction should also be highlighted. The solid waste
problem in many countries is so severe that landfills are at their capacity. EU Member
States are now developing incentive programs to meet solid waste reduction goals. One
focus of these programs may well be the construction industry, as studies indicate that
25% of the materials in landfills are building-related [7]. Deconstruction reduces the
amount of C&D waste produced during site clearance, thus contributing to waste
reduction efforts. Deconstruction also results in significantly greater protection to the local
site, including the soil and vegetation, as well as creates less dust and noise than
demolition [6].
5. CONSTRAINTS IN THE PROMOTION OF DECONSTRUCTION
Despite the deconstruction’s advantages over other C&D waste management
alternatives, there are also some other parameters that need to be considered. Modern
materials such as plywood and composite boards are difficult to remove from structures.
Moreover, new building techniques such as gluing floorboards and usage of high-tech
fasteners inhibit deconstruction. Thus, buildings constructed before 1950 should ideally
be targeted for deconstruction. Asbestos-containing materials encountered in buildings,
are another issue of concern. Used in more than 3,000 building products, asbestos may
be found in pipe, duct, wall and ceiling insulation, ceiling tiles, roofing, siding, vinyl sheet
flooring, wallboard, plaster, and window caulking. Proper removal of asbestos-containing
materials requires special equipment and training [6].
There are many factors that could limit potential demand for building materials acquired
through deconstruction. Among others, the lack of public and/or contractor awareness
about the availability of salvaged materials, the lack of awareness of the significant price
difference between new materials and salvaged ones, as well as the lack of awareness
about the environmental benefits of using salvaged materials are three major reasons for
the slow penetration of this alternative in modern C&D waste management. In addition,
the “hit or miss” problem of not being able to find a salvaged material when needed, or
enough of a particular salvaged material to complete the project, as well as perceptions
that salvaged materials are inferior, further exacerbate this attitude.
Another major drawback of deconstruction is that in almost all cases this alternative
requires significantly more time than demolition. Building removal is generally carried out
under very tight temporal constraints. The lengthy process of getting demolition permits
often narrows time availability for the deconstruction of a building. Once a permit is
secured, developers are under pressure to demolish the building the soonest, in order to
make up for financial losses incurred while waiting for the permit. Thus, there is more
financial pressure to clear the site quickly and further disincentive to promote
deconstruction [6].
6. CONCLUSIONS
Deconstruction is a new term used to describe an old process. As its primary purpose,
deconstruction encompasses a thorough and comprehensive methodology to whole
building disassembly and seeks to maintain the highest possible value for materials in
existing buildings by dismantling them in a manner that will allow the reuse or efficient
recycling of the materials that comprise the structure. Salvaging the materials from
structures reduces waste, preserves the energy originally used to create the materials
and therefore lessens the need for new materials. Deconstruction is widely considered as
a significant step toward sustainability.
Deconstruction is emerging as an alternative to demolition around the world. Architects
and builders in the past and often today still visualise their creations as being permanent,
thus not making any provisions for their future disassembly. Consequently, techniques
and tools for dismantling existing structures are under development and research for
supporting modern techniques of deconstruction is ongoing at institutions around the
world. Designing buildings in a manner that they could easily be disassembled in the
future is beginning to receive more attention lately by architects [3].
Future efforts should focus on addressing disincentives for demolition. A reasonable
disincentive option could be the increase landfill tipping fee for C&D debris. Moreover,
there is a need for support to salvaged-materials collection centers that provide
incentives for contractors to seek alternatives to demolishing structures and disposing of
C&D waste. Other disincentives include timing problems. After waiting a lengthy period of
time for a demolition permit, contractors face financial pressures to demolish the structure
as quickly as possible in order to proceed with its redevelopment and recoup some of the
capital lost while waiting for the permit. Streamlining the permit process, especially
regarding deconstruction projects, could make this particular C&D waste management
alternative more feasible [6].
Under this framework, the DEWAM project aims at increasing the community’s
awareness in environmental issues by providing the appropriate information in the field of
C&D waste management. More careful consideration of the priorities for disposal of
materials from C&D operations needs to be underlined. In time, this would lead to the
minimisation of virgin materials extraction and the energy needed to process used
materials for further use, while it will also contribute to the increase of landfills’ useful life.
ACKNOWLEDGEMENT
DEWAM project is co-financed by E.U.-European Social Fund (75%) and the Greek
Ministry of Development-GSRT (25%).
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(07 May 2007).
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International Council for Research and Innovation in Building Construction (CIB),
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