Organization: BRE
Publication Date: 1 January 2013
Page Count: 68


Waste from construction, demolition and excavation represents the largest waste stream in the UK, at an estimated 77.4 million tonnes in 2010[1]. Of this, at least 17 million tonnes is inert waste from demolition[2], such as concrete, bricks and soils. Virtually all of this material is currently reused or recycled, either on the same site in the follow-on construction, or shipped off site for reuse and recycling elsewhere. Similarly, other demolition waste types, such as solid timber, tend to be reused or recycled. All of this leads to high diversion from landfill rates for demolition waste, typically over 90%. However, there is growing concern in the demolition sector that it may not be possible to improve, or maintain, these high recycling rates into the future, owing to the increasing prevalence of difficult demolition waste.

Difficult wastes (ie wastes that are difficult to recover) are becoming more widespread during major refurbishment and demolition of buildings in the UK. Each year the National Federation of Demolition Contractors (NFDC)* carries out a survey of its members, and the amount of waste going to landfill has increased in recent years, as a result of the changing composition of demolition waste.

Current products in use that have reached the end of their life and may be classed as difficult wastes can include batteries, solvents, insulation products containing ozone-depleting substances, waste electrical and electronic equipment (WEEE), smoke alarms, certain flooring products, and asphalt-based roofing products; others may also be apparent in the waste stream. They are termed 'difficult' as they may be problematic to recover, which could be due to their material composition, techniques of demolition/strip-out, contamination, or their low value, and as a result they are likely to end up in landfill. Some may also have relatively high environmental impact, because of their hazardous qualities, high embodied energy or global warming potential, and so an inability to recover these products at the end of their life increases their overall effect on the environment.

Products that may be considered difficult wastes in the future may emerge from modern methods of construction (MMC). The use of traditional brick-andblock construction is still predominant in the UK, but housebuilders are under increasing pressure to ensure that they make significant progress in achieving the target set by the government for zero-carbon homes by 2016 and to meet future housing demand. This objective for housebuilders would suggest an increase in the number of homes being built using MMC in the future. There is little knowledge in the housebuilding sector regarding the future recyclability of the materials incorporated in buildings using MMC. It is predicted that when these houses reach the end of their life, which is defined as 60 years using whole-life costing accounting, it is likely that some of these materials will not be easy to recycle. Other future difficult wastes may result from systems used in intelligent buildings, and from the development of innovative products within the construction sector.

This report details the findings of a research project funded by the BRE Trust, entitled Difficult demolition wastes  now and in the future. This project was undertaken by the resource efficiency team at BRE with assistance from the NFDC.

The overall aim of this project was to provide costeffective and practical recovery guidance for difficult demolition wastes. This included the following:

• Provide an understanding of difficult wastes entering the demolition and refurbishment waste stream, both now and potentially in the future, in terms of type, amount, issues and current recovery routes.

• Prioritise difficult wastes for further action by using agreed criteria considering:

- environmental impact

- amount being landfilled

- cost

- usage

- recovery routes.

* More information on the National Federation of Demolition Contractors (NFDC) can be found at: http://www.demolition-nfdc.com/