FEATURE
Architects and engineers can contribute to the DfD movement by designing buildings that facilitate adaptation and renovation . Using Canada as an example , buildings are the largest consumers of raw materials and energy and the biggest contributors to the waste stream by weight , which equates to 3.4 million tons of building materials sent to landfills annually , representing an estimated 1.8 million tons of incorporated carbon .
DfD is a strategy that seeks to extend the life cycle of buildings and their components , allowing the building to be updated , maintained , and modified more easily ; but , at the end of its useful life , disassembly still allows for the more efficient collection and reuse of materials and components . Managing the return and recovery of products and materials from companies , demolition sites , and material recovery facilities back into the value chain is the role of reverse logistics – a fundamental principle of the circular economy that allows product materials to be recycled , reused , and remanufactured .
DfD attempts to ensure that after dismantling , the materials have a known and well-considered destination . This can generate a number of benefits , including reducing waste and greenhouse gas emissions in buildings ; improving the resilience of supply chains in construction ; creating new economic , and employment opportunities , providing social benefits , and improving natural ecosystems through lower resource consumption .
CORTESIA DE NATURALLYWOOD . COM
Designing for disassembly requires a mindset that requires professionals to rethink the way buildings are put together so that the materials can be disassembled and reused , maintaining both their resource and carbon value .
For architects , DfD is a difficult concept , as they conceptualise their buildings as being timeless and no architect wants to spend intensive labour creating a building only to have it torn down . The main problem faced today to practice deconstruction is that architects or builders of the past designed their creations to exist forever and did not make the necessary provisions for disassembling in the future . Even today , materials are not produced keeping recycling in mind . Moreover , even though architects want to design sustainable buildings that can later be reused for other purposes , the clients don ’ t want to opt for new building techniques as they are accustomed to and prefer traditional techniques . But architects can contribute to the environment by designing buildings that facilitate adaptation and renovation .
BUILDINGS DESIGNED FOR DECONSTRUCTION
About 25 % of demolition waste can be reused , while 70 % can be recycled . There are certain construction methods and materials that make this process easier .
Buildings that have been designed with deconstruction in mind are often easier to maintain and adapt to new uses . Saving the shell of a building or adapting interior spaces to meet new needs ensures that new structures have a small environmental impact . The current trend in sustainable architecture involves the use of high-grade durable material .
The theoretical model works very well . But in practice , things are a lot more complex . Demolitions are usually carried out quickly , making it impossible to reuse a large part of the materials . First , it is essential to address the proper disassembly and separation of the parts that make up the building . But it is also essential that the project , from the beginning , seeks methods and solutions that reduce or eliminate waste , including products that are easily detached and disassembled as well as good quality materials that allow reuse and avoid harmful and polluting chemicals .
MASS TIMBER AS A DESIGN FOR DECONSTRUCTION STRATEGY
The decision to choose a material or construction system , naturally , will not depend only on the requirements of disassembly . To aid in this selection , the life cycle assessment is a common method that helps shed light on the impacts of a product or process , from the beginning of the process ( extraction of raw material ) to the end of the process ( reuse , recycling , or disposal ).
According to the Circular Economy & the Built Environment Sector in Canada , using wood products – specifically mass timber ( gluelaminated timber and cross-laminated timber ) can reduce the building ' s carbon footprint in several ways :
First , wood is a renewable resource , and its growth takes place through photosynthesis and not through mining or extraction . Trees grow in almost all climates and using local species can greatly reduce the amount of energy expended on transport . When a tree is harvested to make lumber and engineered wood , it stores carbon in the building . When another tree is planted in its place , it will also absorb and store carbon . Finally , because wood is versatile and durable , it can be disassembled and then reassembled into other buildings or other wood fibre products , sequestering the carbon even longer as long as it stays out of landfills .
And , of course , as with every industry today , technology also plays its part . A report by Delphi Group and Scius Advisory points out
24 OCTOBER / NOVEMBER 2021 // www . timberiq . co . za