Sustainability and environmental concerns are becoming ever more important in construction projects. While using eco-friendlier materials and building methods are areas of increasing focus, ensuring that there is as little waste as possible is another way to reduce the environmental impact of construction. For example, in England alone, 63% of the total waste created in 2016 was attributed to construction, demolition, and excavation waste (according to the Construction Leadership Council1). Meanwhile, in the USA, construction and demolition debris in 2015 was nearly 2.5 times the municipal waste generated, according to the US Environmental Protection Agency’s construction snapshot2 and national overview3.
Recovery rates of construction waste can be quite high, but there is always more work that can be done to drive down waste generation at the source. As one of the biggest contributors to waste globally, the construction industry must think of new ways to manage and reduce their waste to help reduce the impact on the environment and conserve natural resources. While achieving zero waste on a construction site sounds nearly impossible, combining a range of approaches can provide a truly waste-free site.
Waste Recovery
Much of the waste that is created by construction can be recovered and downcycled as aggregates, such as concrete, bricks, and asphalt. However, other types of waste can also be recovered and then used for other purposes. For example, plasterboard can be broken down and recycled into new plasterboard, while cardboard is already widely recycled back into new cardboard. Polythene can also be washed and processed into pellets, which can then be used for a variety of applications.
Energy from Waste
Deriving energy from waste is where the waste material is used as fuel for energy, such as electricity. For example, wood can be collected and used as biomass fuel, food waste from site can be used at an anaerobic digestion facility to create electricity from the gases and agricultural fertilizer, and other general waste that cannot be recycled can be incinerated for electricity (Refuse Derived Fuel).
Off-site Construction
Removing the majority of the construction work from the job site and instead moving to prefabricated or modular components can also help achieve zero waste in construction. The greater precision means that less materials are wasted, and the waste that is generated can be recovered more easily and either recycled or used to provide energy.
Minimizing Waste
While the waste that will be produced on a job site is the direct result of the construction works, preventing this begins in the design stage. Optimizing designs to use fewer materials, specifying recycled materials, or choosing components with a longer service life can help drive down the waste that is generated on site in the first place. Other approaches include specifying materials that have a future purpose beyond the life of the building, or designing structures which can be easily adapted to other uses, maintained without creating waste, and deconstructed so that materials can be reused. Even designing more accurately can help avoid rework and wasted materials, avoid overestimating quantities, and reduce the amount of inaccurate data in a project.
A New Mindset
What is clear is that to avoid waste in construction requires a new mindset – a shift from “construct and dispose” to “circular construction” where making the most of our resources is a common practice. If we do this, we really can achieve zero waste in construction.
Sources:
1 https://www.constructionleadershipcouncil.co.uk/wp-content/uploads/2016/05/ZAW-Report-Final-Draft-25-February-2020.pdf#:~:text=Zero%20Avoidable%20Waste%20%28ZAW%29%20in%20construction%20means%20preventing,assembly%20of%20buildings%20and%20infrastructure%20through%20to%20deconstruction.
2 https://www.epa.gov/sites/default/files/2020-04/documents/construction_snapshot_3-31-20.pdf
3 www.epa.gov/facts-and-figures-about-materials-waste-and-recycling/national-overview-facts-and-figures-materials
