Duncan Baker-Brown recently claimed this in an article on Construction21, I guess, based on the fact that he also said, “We know that the construction industry in the UK wastes approximately 20% of the material delivered to a building site”, and I’m assuming he thinks all this waste is only going to landfill or incineration; in other words that none of it is being recycled.
So does any of this stand up to scrutiny?
The UK Department for Environment, Food and Rural Affairs (DEFRA) provide statistics on the recovery of UK construction and demolition waste (see page 7) , and between 2010 and 2014 (the last time the figures were provided), the recovery rate rose from 87.6% to 89.9%, so it is clear that the assumption that 100% of waste from construction is going to landfill or incineration is incorrect, although prior to the Landfill Tax (introduced in 1996) and the Aggregates Levy (introduced in 2002), this might have been closer to the truth. For example a Construction and Waste Resources Platform (CWRP) Report calculated the recovery rate for construction and demolition waste in 2005 to be just over 50%.
Next let us consider whether 20% of the material delivered to a building site is wasted? The same DEFRA statistics above stated that 55 million tonnes of construction and demolition waste were generated in 2014.
The Construction and Waste Resources Platform (CWRP) published a “An overview of UK demolition waste” in 2009 which estimated that 31.8 million tonnes was due to demolition in 2007. Assuming this is has reduced by 25% to account for the economic downturn, then 31 million tonnes of waste are caused by construction alone.
So how much material is used in construction?
- 225 million tonnes of aggregates (of which 28% were from secondary sources)
- 13 million tonnes of cementitious materials
In addition, the following were used in construction:
- 2 billion bricks (BEIS) (4 million tonnes at conservative 2 kg a brick)
- 5 million tonnes of stone (source)
- 3.3 million tonnes steel (29% of 11 million tonnes (steelconstruction.info, ISSB))
- 1.33 million tonnes bitumen (EAPA)
- 0.75 million tonnes of plastics (23% of 3.3 million tonnes (BPF)
- 3.7 million m3 UK produced and 6.6 million m3 of imported sawn timber (Forestry Commission) (3.8 million tonnes sawn timber at 375 kg/m3)
- 3 million m3 UK wood based panels and 3.4 million m3 of imported wood based panels (Forestry Commission) (4.5 million tonnes wood based panels at 700 kg/m3)
- 0.7 million tonnes of plaster and 200 million m2 of plasterboard (DTI) (2.45 million tonnes assuming 12.5mm plasterboard at 700 kg/m2)
- 0.5 million tonnes flat glass (estimate)
- 0.25 million tonnes aluminium (25% of 1 million tonnes)
In total, this gives a minimum consumption of 263 million tonnes of construction materials.
If we compare 31 million tonnes of waste to 263 million tonnes this would give a maximum wastage rate of 12%, much lower than 20%. And as 89.9% of this is recovered, then only 1.2%, or 3.1 million tonnes of construction materials are going to landfill or incineration.
So in reality, you would need to build 83 houses before one house worth’s of construction materials were sent to landfill or incineration. Quite a difference from 5 houses!
Image courtesy of WRAP.