In a typical year an estimated 25 million tonnes of construction waste ends up in landfill without any form of recovery or reuse. Understandably, successive UK Governments have set out to reduce construction waste to landfill, for economic and environmental reasons.
“Adopting circular economy principles could significantly
enhance global construction industry productivity, saving at least
US$100bn a year.” —World Economic Forum
The traditional approach adopted in construction is the linear model, where raw materials are converted into waste. Typically, this involves end of life buildings stripped to their shell and demolished, whilst a new replacement structure is built on the existing footprint using fresh materials.
Take Make Use Dispose
The model illustrated above contends that any materials used in a building can only be used once before being disposed of and it fails to recognise the supply of raw materials is finite in addition to the impact that excessive use of raw materials has on the environment. On the other hand, the circular economy can be summarised by 3 key principles:
Designing out waste and pollution.
Keeping products and materials in use; and
Regenerating natural systems.
Circular construction seeks to eliminate waste production at all stages of the build process, from procurement and design through construction and into operation and then eventual end of life destinations. Circular construction also seeks to reduce the demand for virgin materials by keeping products and materials in use for as long as possible and using recovered materials. Currently, the level of waste in construction contributes over a third of the UK's total yearly waste amount and comes in a variety of forms including excavated materials, incorrectly order materials and packaging. The three principles required for establishing a circular economy are:
Eliminating waste and pollution.
Circulating products and materials; and
The regeneration of nature.
It follows in a circular economy that buildings will have a longer life cycle than traditionally has been the case, this can be achieved by considering at an early stage, for example;
Deconstruction.
Material recycling; and
Modular construction systems.
The main causes of the construction's environmental impact are found in the consumption of non-renewable resources and the generation of contaminant residues, both of which are increasing at an accelerating pace. End-of-life buildings can be deconstructed, thereby creating new construction elements that can be used for creating new buildings and freeing up space for new development. Modular construction systems can be useful to create new buildings in the future and have the advantage of allowing easier deconstruction and reuse of the components afterward. Although a very laudable idea, just how practical is a move towards a circular model, something that will be discussed in Part 2 of this blog, coming soon?
What’s in it for construction?
As with so many new initiatives the construction industry does not readily adopt new methods of working, despite the perceived benefits of adopting a more sustainable approach are seen as;
Increased brand value / corporate image and reputation
Cost savings through consideration of life cycle costs, through the sustainable use of energy, water, less waste and
The use of fewer raw materials.
Issues such as the circular economy and many other challenges facing construction are discussed in detail in the 5th Edition of New Aspects of Quantity Surveying to be published in Spring 2023.
Duncan Cartlidge