With last month’s introduction of mandatory Site Waste Management Plans (SWMPs) in England, waste is at the top of the construction industry’s agenda. Mervyn Jones, Construction Programme Manager at WRAP (Waste & Resources Action Programme) looks at the opportunities to reduce waste at the design and specification stages of a project.
When it comes to re-use and recycling, the UK construction industry has made significant progress in recent years. An increasing number of organisations are making a strong commitment to waste, often over and above the Government’s target of halving construction waste to landfill by 2012, as proposed in the draft Strategy for Sustainable Construction (2007).
Now industry focus is turning to minimising waste and a SWMP is one tool supporting the industry in this, enabling contractors to predict and report the waste generated by a project and understand where this waste is produced.
With this knowledge, contractors are able to work closely with all parts of the supply chain to identify opportunities to minimise waste throughout the construction process. It is, however, at the design and specification stages where the most gains can be made and there are three main ways in which this can be achieved:
Designing to standard components
Significant volumes of waste are generated on site by cutting materials to fit the design specification. The design directly influences the level of waste produced on site and one option for reducing waste is by taking into consideration the standard sizes of materials on the market and designing with these in mind or reducing wasteful design elements. One of the most common materials wasted on site is plasterboard and working to the board’s standard heights and widths could make a significant difference to the amount of usable material that ends up in the skip. Timber is another example, where significant wastage is caused on site by offcuts.
Where design teams are tasked with looking at wasteful elements during this stage of the process, not only is material resource efficiency greatly improved, the industry is also able to save costs through the reduction in materials and disposal. All decisions taken to minimise waste can also be detailed in the project’s SWMP, demonstrating the proactive approach taken to reduce waste.
It is widely estimated that over-ordering of materials takes place on most projects, however most of these additional materials will end up in the skip, but they could be stored and taken to the next project. In fact, around 10 percent of materials arriving on site end up in the skip unused or damaged - not only is this a material waste, it is a significant financial one. A recent Environment Agency report estimated that around 10 million tonnes of unused construction products are put in skips each year through wastage – equivalent to about £1.5 billion.
Alternative delivery options available to contractors, such as consolidation centres, and supply chain logistics, can help to reduce the impacts of over-ordering and ensure materials are on site when needed and in the quantities required. ‘Just in time’ deliveries will also ensure that materials are not left on site where there is the potential for damage.
Using off-site manufacture
Another area where waste can be reduced is through the use of modern methods of construction. A series of WRAP case studies into the waste potential of a number of off site construction methods, including volumetric construction, timber frame, precast concrete and light steel frame have all showed a significant reduction in waste, with typical savings achievable between 40 and 70 percent, with some as high as 90 percent compared to traditional construction methods.
Off-site construction also can also offer contractors wider benefits in terms of speed of construction and alleviates problems caused by the skills shortage. At the same time, the factory environment enables greater recycling potential, reduced wastage through errors and better quality control, helping contractors meet their waste reduction targets.
The importance of the industry taking a holistic approach to construction waste cannot be underestimated. Everyone in the construction process – client, designer and contractor - has a responsibility for waste and has a role to play in reducing it. The increased use of SWMPs is supporting the industry in predicting the waste of a project. Armed with this knowledge of where the biggest waste streams are generated, the industry is able to identify where savings can cost-effectively be made to stop waste being produced in the first place. By working closely with the whole supply chain, contractors can work to reduce waste not only on site but throughout the whole process. It is this approach that will ultimately have the greatest impact on helping the industry meet increasingly stringent targets on waste.
Access a suite of resources on minimising and managing construction waste, including a SWMP Template and guidance on designing out waste, at www.wrap.org.uk/construction