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Buildings can last many generations of people, and flexible design allows designing a building with the end of life recovery of the materials in mind from the outset. It is about minimizing resource use by thinking about resource efficiencies at every stage of the project, from conception to end of life. Incorporating flexible design for deconstruction into developments will contribute to more sustainable built environment by extending the useful life of a building and optimizing materials reuse and recycling potential at the end of the buildings life.In Australia buildings have been estimated to consume 30 - 50% of available raw materials, account for 25 - 40% of final energy consumption and generate about 40% of waste to landfill in OECD countries (OECD 2003) (OECD 2002). From an Australian perspective in 2005, building materials were responsible for the generation of approximately 2% of total Australian greenhouse emissions and constitute about 10% of the overall greenhouse impacts of buildings (the rest is from energy consumed for building operations).

To date, the efforts of government and industry to improve the environmental performance of buildings have mainly focused on measuring and reducing their ‘operational’ impacts particularly the day to day use of energy and water, and as these opportunities become harder to realize, the embodied impacts of the materials become the low hanging fruit.

By considering flexible design and designing for deconstruction developers have the opportunity to deliver significant savings in total materials flows, with economic benefits to building owners, facility managers and tenants over the building life.

Key Principles

1. Design buildings to be adaptable to different occupancy patterns in plan, in section and in structural terms.
   
2. Ensure that buildings are conceived as layered according to their anticipated lifespans.
   
3. Ensure all components can be readily accessed and removed for repair or replacement.
   
4. Adopt a fixing regime which allows all components to be easily and safely removed, and replaced through the use of simple fixings. Design connectors to enable components to be both independent and exchangeable.
   
5. Use only durable components which can be reused. Try to use monomeric components and avoid the use of adhesives, resins and coatings which compromise the potential for reuse and recycling.
   
6. Pay particular attention to the differential weathering and wearing of surfaces and allow for those areas to be maintained or replaced separately from other areas.
   
7. Carefully plan services and service routes so that they can be easily identified, accessed and upgraded or maintained as necessary without disruption to surfaces and other parts of the building.

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Reuse of materials – resource minimisation

Due to projected growth in building demand over the next fifty years in Australia, total materials use by mass is projected to grow by almost 40%; global warming potential associated with materials used is projected to grow by 40%, and water use in building materials provisions is projected to increase by 63%.

Recycling only partially addresses the construction waste problem, because it can use up considerable resources in re-processing and transportation.
Only a fraction of construction elements are actually reclaimed and reused for their original purpose, despite this often being the best environmental option at a local level. Flexible Design for Deconstruction is one solution to these issues.

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The deconstruction plan

Without a comprehensive deconstruction plan for the future, it is almost certain that designed re-usable building elements will be destroyed unnecessarily. The Plan should be issued to all parties at the outset of the contract to ensure a construction process that enables the deconstruction plan to operate.

For a successful deconstruction plan, which is a part of the overall Design for Deconstruction (DfD) detailed plan, make sure the following tasks are undertaken:

1. Statement of strategy for DfD relating to the building
   • Demonstrate the strategy behind the designed re-usable elements and describe best practice to ensure they are handled in a way which preserves maximum re-usability
2. List building elements
   • Provide an inventory of all materials and components used in the project together with all full specifications and all warranties, including details of manufacturers
   • Describe the design life and/or service life of materials and components
   • Identify best options for reuse, reclamation, recycling and waste to energy for all building element
3. Provide instructions on how to deconstruct elements
   • Provide up-to-date location plans for identifying information on how to deconstruct buildings.
   • Where necessary add additional information to the “as built” set of drawings to demonstrate the optimum technique for removal of specific elements.
   • Describe the equipment required to dismantle the building, the sequential processes involved and the implications for health and safety as part of the CDM requirements.
   • Ensure that the plan advises the future demolition contractor on the best means of categorising, recording and storing dis- mantled elements.
4. Distribution of DfD Plan
   • Revise the plan as necessary and re-issue to all parties at the handover stage, so that there is maximum awareness of the DfD requirements for the future, including building owner, architects and builder.
   • Place copies of the revised Deconstruction Plan with the legal deeds of the building, the Health and Safety file and the maintenance file.

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Case Study - The Steel House (Modabode)

The Modabode steel house is an excellent example of prefabrication and delivery to site to reduce waste and construction time. The house can also be easily reconfigured providing a flexible design for changing needs and can be deconstructed at the end of life.

Web address www.modabode.com.au

Left: The Modabode house is prefabricated and transported to site.

Right: The Modabode house is lifted into place

Left:The house is modular and can be configured according to need.

Right: The Modabode house is designed to be readily removed from site and deconstructed so that the materials may be used elsewhere.

The house could be considered as a temporary repository for building materials, can be added to or removed from site easily and the site can be reconditioned to its natural state.

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Case Study - Deconstructing weather damaged buildings, Vilanculos, Mozambique.

This case study is drawn from Vilanculos in Mozambique. In February 2007 a cyclone hit the East coast of Mozambique causing widespread damage to buildings. The example shown below is a market place building donated by the Irish people to the people of Vilanculos. The building was completely destroyed, with the roofing being ripped off and the steel frame being twisted into an unuseable mesh. Building products, particularly steel beams and roofing are a valuable commodity in fast developing Mozambique. These materials are difficult to reclaim due to the connections. The steel frame has been welded, rather than bolted together, making deconstruction energy intensive. The bricks in the construction however can be easily reclaimed to the high lime content in the mortar.

The market building in Vilanculos in Mozambique after the February 2007 Cyclone.

Due to the unavoidable consequences of climate change we will experience more extreme meteorological events. Design for Deconstruction can contribute to reclaiming resources from damaged buildings.

This twisted mass of metal could have been a valuable resource for reconstruction. Due to connections being welded it is difficult to reuse. (photo: Tom Davies, Mozambique 2007)

A soft mortar has been used in this brick construction (high lime content). This means that the bricks can be easily cleaned, reclaimed and used again in a local project. The concrete surface however has become a difficult assembly to dispose of. (photo: Tom Davies, Mozambique 2007)

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Case Study - reusing materials, The Old Leura Dairy, Blue Mountains

The Old Leura dairy is constructed from more than 90% reclaimed materials. The owner builder Michael Hennessey describes the complex of buildings as a repository for materials. The materials have been sourced from local reclamation yards and from demolition sites throughout the Blue Mountains. Materials come from old bridges, hardwood weatherboards that are over 100 years old, and even old sheep shearing sheds.

This end view shows how bridging timbers, weatherboards, bricks, windows and roofing material have been reclaimed and reused.

This picture shows how the connectors and detailing has been considered for deconstruction, allowing flexibility of the design and eventual reclamation of the materials.

The connections aid reuse. In this picture rail sleepers have been used in the steps, and flooring from an old wood shed is used on the ramp. The ramp timbers have been in a wool shed for over 100yrs, and have been soaked in lanolin over time naturally treating the timber.

This picture shows how reclaimed bricks have been used to pave a garden area. Also timbers not being used in the structure can be stored in the garden and double up as seating.

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Key Issues

Benefits

Lengthening the service life of buildings – A building that is designed to be adaptable will have a longer service leading to a lower environmental impact per year of life of the building. Current practice for most buildings is based on a 60 year lifecycle. This is very short when one thinks of previous generations of buildings that have stood easily for 200 years or more.

Economic benefits - Economically there are significant potential benefit from increasing resource recovery. Preliminary analysis suggests recovering an additional 5-10% of the value of building materials currently resulting from demolition (i.e. 5-10% of $1.5 billion, or $75-150 million per year) may be a reasonable target. Although most raw materials will not be exhausted in the short term, localised shortages of some materials are projected over the period to 2055, e.g. washed sand and gravels.

Waste Minimisation - A significant percentage of total life-cycle impacts of buildings occurs at the end of life, either through direct impacts from the demolition and waste processes, or through the lost recycling opportunity and associated additional requirements for new materials. Currently about 60% of construction and demolition (C&D) waste is recycled. The rate of recovery tends to be higher for metals and other high value materials, but many materials that are recycled, such as concrete, are ‘downcycled’ into road base and other low value uses. Extending the useful life of buildings and additional reuse and recycling offers opportunities to reduce costs and avoid the impacts to the environment that would result from otherwise necessary production of new materials. All resources have an initial natural source, a rate of extraction, and a natural sink, where unusable waste finally rests. A key consideration is to ensure that our rate of extracting materials is not greater than the earth can naturally assimilate in any one place at any given time.

Saving landfill – The landfill situation is now critical, with local councils sometimes to resort to transporting waste further and further afield or else burning it and releasing pollution into the air. Construction product reclamation sites are becoming more common place, and can be a useful local source of materials for developments.

Minimising transportation – The cost of transportation is becoming a larger component of the cost of building materials and is also a large component of the embodied environmental impacts of building materials. By designing for deconstruction we can ensure that future buildings will have a source of building materials in place. We spend as much energy transporting our construction materials around the country as we do making them in the first place.

Energy consumption of building materials industry as a proportion of total UK industry energy consumption (1996) (BRE, 2008)

A new industry - Design for deconstruction should aim to reduce the rate of extraction of the construction materials by maximising the re-use of construction elements. This means “future-proofing” against waste and pollution as far as possible by considering future scenarios for building use. As design for deconstruction becomes common practice material cycles will be become more closed with waste products playing more and more of a role in the overall resourcing of construction materials.

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Risks

Comprehensive disassembly plan – The Life of a building could be greater than 200yrs, and a flexible design should facilitate that. There is a risk that at the end of life of the building that the deconstruction plan has been forgotten, and that the building is demolished due to convenience and the benefits of deconstruction not realized. The disassembly plan must be clear and apparent through the lifetime of the building. In essence, someone must keep the instructions! It may be that the disassembly plan is lodged with the building managers, as there will be a requirement for the building manager to manage maintenance of the building over time. The disassembly plan could be included in the building maintenance plans, facilitating ease of replacement of materials and products as well as keeping the overall disassembly plan front of mind.

Risk of adopting new practices – Will the market adopt the new innovation? There is always a risk to new and developing practices. There is a risk in choosing new materials and products that a better one is developed soon after specification/purchase, and that the specified product is obsolete at construction. This is an inherent risk with all new things and is negligible.

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Savings

Materials savings - Key construction materials can be saved with high re-use potential at the point of demolition. Steel, masonry, concrete and timber comprise the vast bulk of construction materials and all offer possibilities for reuse where fixings have been designed to facilitate this. Materials reuse saves on reprocessing and transportation costs associated with recycling. Only a fraction of construction elements are actually reclaimed and reused for their original purpose, despite this often being the best environmental option at a local level.

Reducing churn - The overall material use in residential renovations in Australia indicates that the original design of many homes is no longer appropriate for current homebuyers (RMIT 2006). Design which incorporates flexibility of future use can help reduce churn by making spaces more readily adaptable. The Australian population demographic is changing with a higher proportion of older people to house over the coming years, and it is likely that houses will need to be adapted accordingly. Flexible design can help reduce the churn rate of materials and products during such renovations.

Maintenance savings – Design for deconstruction can increase the longevity of the building. Future risk and cost can be designed out by ensuring that building elements and products can be quickly and easily maintained and replaced.

Time and materials savings after extreme meteorological events - Worldwide we are experiencing a higher occurrence of extreme meteorological events due to the unavoidable consequences of climate change (See Adaptation to Climate Change Section). This includes cyclone and flood damage. In the clear up operations much time could be saved deconstructing steel framed buildings if the elements had been designed for deconstruction (See Villanculos, Mozambique Case study).

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Costs

Design and procurement detailing - It is likely that initially the design phase will take longer and therefore be more costly. This is always the case as new practices develop and take hold. Reused materials can often be more expensive as reconditioning them has taken time.

Higher premium on materials/components - For similar reasons to the design and procurement phase taking longer, there is likely to be a higher cost for materials and components initially. As manufacturers begin to address the demand for new products with fixings and fasteners that facilitate deconstruction they will recoup the sunk development costs with premiums on new and innovative products and materials. In time as the cost will decrease as competition increases. There is also a financial disincentive for manufacturers to produce materials that can be used indefinitely as they will not be benefiting from repeat business. It may be that manufacturers adopt different philosophies to the supply of building products and materials, and in fact adopt a leasing model rather than a sales model.

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Barriers

New practices/change – The building profession can be relatively reluctant to change. Traditional practices have been learnt through years of apprenticeships and new practices can take time to be adopted. The list of benefits is long, and these need to be communicated to the profession to promote change. Changing practices also provides challenges for developers and contractors with set methods and procedures, which need to be handled with consideration. It is the early adopters who will recognize the benefits in the long run.

Added Complexity of building products – With added complexity comes a reluctance to adopt new practices, as the easiest and quickest method is most likely to be adopted.

Additional Cost – As discussed previously, it may be that the initial investment in the building will be greater. If the design for deconstruction works the initial higher cost will be paid back over time with the savings described previously. The savings that flexible design for deconstruction offers must be articulated clearly when considering the extra cost.

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Benchmarks

Case studies – There are multiple examples of buildings in across the world of buildings that have been adapted for new uses, and in some cases are over five hundred years old. For example churches that have been adapted to housing, warehouses that have been converted amongst many other examples. Good design lasts! There are also case studies of projects that have been constructed out of reused materials, such as the case studies supplied in this section.

Lessons from other industries – There are steel buildings, particularly industrial buildings that are designed to be deconstructable and moved. They are fabricated off site, transported to site and constructed. At the end of their useful life they can be deconstructed and moved or even stored until they are required somewhere else (Butler Buildings) Steel building practices, Commercial buildings. The same principles can be applied to any building material or product (concrete prefabricated panels and timber products) as long as they are designed for reuse.

Houses of the Future project 2004 - The Australian Houses of the Future project showcased six houses made from different materials (steel, concrete, timber, glass, cardboard, bricks). The houses were designed to be modular, deconstructable and transportable and demonstrate how each material could contribute to better environmental performance for the future. The steel house is shown in a case study.

Industrial ecology - An industrial ecosystem mimics a natural ecosystem through an interacting web of inputs, processes and wastes which “close the loop” by turning wastes back into resources. Design for deconstruction can close the waste loop in two ways; firstly by re-using existing construction elements where practical and secondly by encouraging the designed elements to be re-used easily and locally. Ideally design for deconstruction should be contained as far as possible within a given regional area, to minimise transportation and maximise the local economy. There are several emerging industrial ecology models including one being incubated by the NSW Department of Environment and Conservation. See also the Kalundborg case study.

Elevator and lift companies - Elevator and lift companies have been deconstructing and maintaining their lifts and elevators in operational buildings for years. They have a history of upgrading and maintaining lifts as new technology arises and there are many lessons to be learned from this industry that could contribute to replacing building elements in situ.

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Development phase actions

Feasibility

If Design for Deconstruction (DfD) is to succeed, it is vital that the whole project team and client are brought on board from the beginning of the project. Different stakeholders in the team will have different objectives and it is important to identify how far DfD can satisfy these and to establish priorities, procedures and lines of communication relating to DfD throughout the construction, maintenance and deconstruction phase of the building’s lifespan.

Feasibility phase actions include:

• Site Assessment – will it support a deconstructable building, now and into the future? Some sites may be in relatively undeveloped areas, where space for deconstruction is not an issue. However this is likely to change over time, and consideration must be given to how the site will look into the future, 100+ years.
• A champion should be appointed for the Design for Deconstruction (DfD) aspects of the project, and a full briefing on DfD to each team member and discusses their role both at collective team meetings and on an individual appointment basis
• Quantity Surveyors need careful briefing on the cost-benefit implications of DfD both in terms of initial construction costs and future maintenance costs;
• Establish DfD targets and benchmarks in terms of the percentage of the building that can be re-used as well as the number of potential re-uses for each existing element;
• Evaluate site constraints, project budget, the purpose of the building, its lifespan and the contract period as crucial determinants of DfD benchmarking

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Planning

• Develop a Strategic Plan for deconstruction that outlines how DfD will be incorporated at each stage of the project.
• Mechanical Engineers should be encouraged, in consultation with the rest of the design team, to design out as much as possible of the active servicing elements in a building and replace these with passive measures that have a longer life span;
• Structural Engineers should ensure that their structural systems are easy to deconstruct and designed for maximum re-use possibilities;
• Other specialists should be briefed and consulted on DfD strategies as necessary;
• Adopt the detailing principles for DfD outlined in Section 5 of this guide as well as other guidance on sustainable design as far as possible; aim to prioritise key principles
• QS to undertake a detailed cost-benefit analysis of low-cost DfD options, taking account of any identified sources of reclamation and offsetting them against the cost of virgin construction resources. For example, if a source of re-usable steel beams of a particular span and size is identified, then the QS and design team should take into account, at the earliest opportunity, how this resource can be “designed into” the building. Priorities should be identified at this stage.
• Evaluate the structural and service options which can maximise DfD within the given constraints
• Agree a list of reductions, which take DfD into account, should the project costs exceed the budget
• Make sure the aesthetics for the project, which are clearly defined at this stage, take account of the agreed DfD strategic plan; sometimes an image can overrule the process!
• Produce a deconstruction plan – (See section above)

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Design

• Use the DfD strategic plan as a framework to develop the details and specifications in tandem with CDM requirements;
• Seek advice from manufacturers on whether, and how, product value can best be maintained through re-use and how products can be certified for re-use;
• Where it has been possible to identify re-usable elements from other buildings, incorporate these in the detailing, provided they do not violate the overall DfD strategy;
• Develop the strategic DfD plan to a more detailed level to take account of drawings, specifications and costs, as part of an iterative process of design;
• Carefully scrutinise standard specifications to ensure that the DfD is not compromised particularly by poor specification of materials, finishes, joints and connections;
• Use three dimensional drawing to aid the understanding of the process of DfD - it reveals hidden aspects of two dimensional drawing in terms of the construction/deconstruction process;
• Fully detail service drawings rather than specifying in outline to ensure full co-ordination for DfD;
• Replacement of elements potential also designs out future risk and cost by ensuring that building elements and products can be quickly and easily maintained and replaced. This is particularly important if they become unacceptable under future environmental legislation, which is an increasingly common occurrence;
• Ensure any alterations to the digital drawings and specification are carefully integrated into a revised set of drawings so that a genuine set of “as built” digital drawings is available for maintenance and deconstruction purposes.

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Construction

• Expertise in DfD should be sought. A major cultural shift is needed in all trades, which recognises the need for construction elements to be more separable. This means balancing the need for quick construction against the future requirements of DfD, such as avoiding excessive mechanical demolition techniques. The contractor can add considerable insight into the construction process required to fulfil the requirements of the deconstruction plan, particularly if a partnering process is instigated to ensure their involvement with the design team at an early stage;
• Once the contract has been agreed, ensure that pre- site start meetings allow time for a thorough briefing and negotiation on the objectives of DfD as part of the project and the most effective means for achieving this;
• Encourage the design team and contractor to source reclaimed materials locally.

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Lot Creation

• How will lot creation constrain deconstruction and material recovery into the future? Ensure that this has been addressed in the deconstruction plan.
  

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Completion

• Provide a contingency budget for changes which occur during commissioning and future maintenance, and the recording of these in the logbook, the deconstruction plan and on drawings;
• Provide for continuing dissemination and transfer of DfD related information during the lifespan of the building to all parties concerned which takes account of any transfer of ownership or upgrading of the building;
• Training for both the users and maintenance team on the DfD aspects of the building will help to prevent maintenance choices which disable the DfD function; this is vital if the DfD strategy is going to work effectively;
• Undertaking post-occupancy evaluations and post-project appraisals to learn if aims of project have been met;
• Provide a comprehensive and digital operating and maintenance manual for the building, complete with logbook to record future maintenance, carefully cross-indexed to aid rapid information retrieval;
• Ensure the manual contains a complete section on the DfD strategy as well as the revised “as built” deconstruction plan and drawings;
• Lodging the deconstruction plan – Ensure that the deconstruction plan is disseminated as per above.

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Bickford, S, Modabode, personal communication, 18th January, website can be viewed at [http://www.modabode.com.au]

Building Research Establishment, 2005, Cleaner More Efficient Deconstruction, Building Research Establishment News, viewed 16th January 2008, [http://www.bre.co.uk/newsdetails.jsp?id=347 ]

Butler Buildings, 2008, Butler is Building Green, Butler Buildings, viewed 14th January 2008, [http://www.butlermfg.com]

Scottish Ecological Design Association, 2006, Design and Detailing for Deconstruction, Scottish Executive (Government), viewed 14th January 2008, [http://www.seda2.org/dfd/index.htm ]

RMIT, 2006, Scoping Study to Investigate Measures for Improving the Environmental Sustainability of Building Materials, Australian Greenhouse Office

Houses of the Future, 2005, Houses of the Future, Sydney Olympic Park Authority, viewed 14th Jan 2008, [http://www.housesofthefuture.com.au/hof_what01.html]