WRAP commissioned a report in preparation for COP15 that assessed the contribution of resource efficiency to overall GHG reduction. Below are some extracts that pick up elements relative to the construction sector and the materials used. The text sections and tables below highlight the choices we are making and where we need to focus on next to improve.
The full report can be read here.
Some summary highlights include:
- Accounting for the impact of imports reveals that the UK’s contribution to climate change is increasing. There is little evidence to suggest that this situation will change in the short term.
- If reducing material input is not an option, re-use and recycling is the next best alternative. 58% of the waste produced from industry, commerce, construction and households is re-used, recycled or recovered, leaving 42% going to landfill (Environment Agency, 200543). Much of this waste will degrade, creating methane, a GHG 25 times more potent than CO2. With landfill at the bottom of the waste hierarchy, policies to divert waste from landfill play a very important role within national waste policies. Whilst considerable reductions in methane emissions have been achieved in the waste treatment sector as a result of reduced emissions from landfill, further reductions are possible. Inevitably, there will be some waste which cannot be recycled (we assume 10%), whereas the remaining 32% of waste to landfill can be recycled back into production, reducing sectoral material demand. This reduces the demand for refuse disposal, whilst increasing demand for recycling facilities. This strategy assumes the following reductions in material input by each manufacturing sector, consequently increasing recycling activities:
- Quick Win – 15% of the raw materials ending up in landfill from industrial and commercial waste are recycled and put back into production by 2020.
- Best Practice – this increases to 50% by 2050.
- Beyond Best Practice – accounting for 10% unavoidable waste, all waste destined for landfill is recycled by 2050.
- This scenario considers three components of service industries: food waste, product optimisation and junk mail. Food waste in service sectors is particularly relevant to the hotel, restaurant and catering industries, which produce approximately three million tonnes of food waste alone, half that arising from UK households. The remaining half comes from retailers, food manufacturers, agriculture and commercial food waste (e.g. hospitals and schools etc.) (WRAP, 200944) . We apply the evidence that half of food wasted by households is edible, to all UK service sectors. Assuming this, the scenarios are as follows:
- Quick Win scenario – service sectors halve their edible food waste by 2020.
- Best Practice scenario – service sectors do not throw out any edible food waste by 2050.
- Beyond Best Practice scenario – service sectors meet the best practice earlier by eliminating edible food waste by 2030.
- Modern Methods of Construction (MMC) or off-site construction offer significant potential to minimise construction waste compared to traditional on-site construction. Several studies have found corresponding evidence that suggests modular homes can reduce waste by 70 to 90%, through better material management. Houses can be made using on average 10% less material tonnage (WRAP, 200746; BRE, 200947; Barrett and Wiedmann, 200448). The scenario assumptions made are:
- Quick Win scenario – 2% of the construction market is met by modular building design by 2020.
- Best Practice scenario – 5% of the construction market is met by modular building design by 2050.
- Beyond Best Practice scenario – 10% of the construction market is met by modular building design by 2050.
- Efficient Use of Existing Infrastructure; Of the 26 million homes in the UK, on average, 25,000 houses are demolished every year and there are currently 3.1% vacant (The Empty Homes Agency, 200949). This scenario explores the option to meet rebuilds by retrofitting the existing stock, with the intention of reducing the input material required by the construction industry, one of the highest impacting sectors. This would involve 7% of homes. Whilst 40%House (Boardman et al., 200550) look at increasing demolition rates in the UK as new builds are designed to be more energy efficient (reducing household energy demand), this scenario has a material focus and considers the indirect emissions embodied in the housing stock. It looks at reducing emissions using the existing housing stock. We know the material requirement for the average new build in the UK is 117 tonnes (Wiedmann and Barrett, 200448). Refurbishment takes out the material demand for the foundations (over 80% of the total material requirement), yet there are key aspects where maintenance is required, such as windows, doors, roof tiles and the interior. This gives us the new material requirement for retrofitting the existing housing stock. The scenario assumptions made are:
- Quick Win scenario – Retrofitting 20% of housing deemed for demolition and vacant properties offsets the need for rebuilding by 2020.
- Best Practice scenario – This continues to 50% by 2030.
- Beyond Best Practice scenario – By 2050, we assume that 90% of these properties are brought back into use, reducing the need for new builds.
- Restorative Economy; Slowing the rate at which products are consumed (literally, “used up”) by increasing their intrinsic durability and providing careful maintenance.
The report concludes with a Recommendations section:
- Prioritise “Quick Wins” and develop a UK strategy for immediate implementation.
- There is a lack of evidence on the possible changes in resource efficiency within industry. This study would have benefited from a greater insight into the role of industry in resource efficiency and the potential for change. There is a need for detailed industry knowledge to understand the feasibility of resource efficiency strategies to individual sectors.
- While all these strategies can be implemented with no significant effect on the overall UK economy, each strategy will cause a structural shift in the economy and there will clearly be winners and losers. Support is needed for industry and consumers to achieve this transition towards a low carbon economy.
- Material efficiency, along with other non-energy related strategies, must be incorporated into UK climate change scenarios, which is currently not the case.
- A greater knowledge of the right policies to counteract the re-bound is required to ensure that all the resource efficiency and sufficiency strategies have their intended effect.