Prioritise reuse over recycling to reduce carbon emissions in construction industry, says expert
Reuse of building materials, such as bricks and steel girders, should be prioritised over recycling in order to minimise carbon emissions, according to Bioregional Development Group reclaimed materials manager Jonathan Essex.
In a webinar called Zero waste equals 100% reuse – towards a low carbon construction industry hosted by web-based discussion tool 2degrees, Essex said: “We are recycling at the expense of the environment. The drive to reduce waste to landfill has increased recycling massively but has also reduced the level of reuse.”
Essex claims that recycling materials that could be reused in certain cases actually increases carbon emissions because of their embodied carbon. He cited research, produced by Salvo – a network of the UK’s architectural and salvage industries - which states that the amount of building materials reused in the ten years up to 2007 has actually fallen by 25%.
Using the example of steel frame buildings, he explained that if half the reclaimable steel was reused instead of recycled for scrap we could save 100,000 tonnes of CO2 emissions each year. Additionally, he spoke of the incentive in the UK to generate energy from wood as biomass, which is competing with wood recycling, pushing chipboard prices up. According to Salvo, wood reuse rates have reduced by 250,000 tonnes in the ten years up to 2007.
“By focusing on reuse and waste prevention there is the potential to actually save more energy and waste than energy recovery and recycling,” explained Essex. “Although energy recovery talks about energy, it only offers the possibility of recovering some of the energy which you get from burning something, whereas when you reuse a product then you can also save all the energy which is used to make the product in the first place and is a waste which occurs during the supply chain.”
Essex believed an overall decision making hierarchy for the construction industry to reduce its carbon emissions and resource use should be followed. This would reduce carbon emissions through a ‘culture of reuse’ from the construction stage through to the built and ‘living’ stage.
This would start with maintenance at the top, going through to change of use through refurbishment, then deconstruction of old buildings and reclamation and reuse of these materials as opposed to recycling. At the fourth level a low carbon new build may be possible, while using high carbon materials on new builds as the last option.