Construction Best Practice
Site waste management/action plans and monitoring
The Site Waste Management Plan (SWMP) should identify who is responsible and training requirements and communication methods. Best practice includes setting targets for the reduction of waste and recycling rates using Key Performance Indicators (KPIs). This is required to gain extra points for the Code for Sustainable Homes and BREEAM. Best practice guidance KPIs and guidance on how to use them can be found at www.kpizone.com and smartwaste.co.uk.
Construction of Olympic White Water facility, Broxbourne
Source: London2012.com
It is now a legal requirement in England for all construction projects costing over £300,000 to write and implement a Site Waste Management Plan (SWMP).
A plan should:
- Consider waste minimisation actions especially at the design stage
- Forecast the amount and type of waste that is likely to be produced and how it will be managed
- Ensure all existing waste legislation is complied with
- Monitor and record waste arisings and how much is reused, recycled, recovered
and disposed of.
There are a number of best practice guidance documents and tools available to assist with site waste monitoring. These include the BRE’s SMARTWaste Plan which is a SWMP web-based tool with an integrated measurement function. Further information
can be found on the WRAP website and at smartwaste.co.uk.
Adopting 'just in time' delivery
Stockpiling of materials on site increases the likelihood of their damage and their becoming waste material. Just-in-time delivery ensures that materials are on site only when they are needed. In addition to reducing the risk of damage, it also reduces storage space requirements and makes way for space for waste segregation and storage.
However, consideration should also be given to the potential increase in vehicle movements that 'Just In Time' delivery can incur.
Re-use of materials
High value materials such as bricks, slates, tiles, beams and architectural details can often be re-used for the same function. This can occur in demolition and refurbishment projects (depending on the integrity of the material following segregation) where particular components are re-used in the same building or sold for re-use.
examples of waste material reuse
| Material | Reuse |
|---|---|
| Broken brick or concrete | On-site levelling or filling holes |
| Cladding material | Use to refit another property |
| Components of old buildings (roof or floor tiles, beams) | Renovation of similar buildings or new 'mock-aged' construction |
| Fittings (door and window frames) | Fit in new or renovated building |
| Surplus construction materials | Return to place of purchase or use on another site |
Sorting of waste on site
Thorough sorting of construction wastes is essential practice to enable effective re-use and recycling. It can also help to identify actions and priorities to reduce waste. Identifying the waste streams and causes of waste generation should be considered at an early stage, and space for segregated waste storage should be allocated on-site as appropriate. The end use of the sorted waste materials can be planned before the construction process commences.
Sorted waste can be compacted onsite to reduce the void space in skips, which reduces the number of skips required and the associated transport. For instance this can be done by chipping or crushing plasterboard waste or by baling cardboard and polythene waste.
Since October 2007, it has been necessary ofr businesses to 'treat' waste before it goes to landfill as a last resort. Treating waste includes:
- Collecting waste streams separately to recycle of the separated components
- Biological treatment such as composting or anaerobic digestion
- Thermal treatment such as incineration
Examples of the materials that can be collected on-site and their potential end treatment are listed in the following table:
| Material | Reuseable/Recyclable |
|---|---|
| Bricks | Reusable*/recyclable |
| Concrete | Recyclable |
| Hardboard | Recyclable |
| Packaging | Reusable/Recyclable |
| Glass | Recyclable |
| Timber | Reuseable**/recyclable |
*costs permitting
**depending on use
Although segregation of waste on site is typically the most practical waste management route, site conditions do not always permit it. Consequently, off-site segregation and recycling can be pursued.
Hertfordshire has a number of permanent waste sites that recycle and dispose of construction wastes. Some are listed on the WasteAware website at: wasteaware.org.uk and BREMAP bremap.co.uk.
On-site recycling of waste
A site waste management license must be applied for if active on-site reprocessing of waste is to be pursued (e.g. crushing and screening of inert waste). For more information on licence applications and the application process go to environment-agency.gov.uk.
Not all sites are suitable for waste reprocessing, as it can present nuisance impacts for neighbouring sites and the costs of equipment rental can be high. In some cases it may be more cost effective to transport waste to a local recycling site. However, if more than approximately 30km away, the environmental benefits of recycling construction materials may be reduced.
Return of materials to manufacturing facilities
Waste material can be returned to the supplier for re-integration into the manufacturing process. This is especially applicable in large projects where a significant amount of waste is produced. This is a practical solution since the same lorry that brings the products onto the site can return to the manufacturer with the waste material. A number of UK manufacturers are now happy to adopt this approach. They include all of the UK plasterboard manufacturers (British Gypsum, Knauf and Lafarge). Pallets and packaging can also be taken back by suppliers and reused.
Information on good procurement practice, manufacturers that take products back, and products that have a high recycled content can be found on the WRAP website here.
Demolition
The treatment of demolition waste and its destiny is best covered in the Demolition Protocol (published by the Institution of Civil Engineers). The protocol sets a method based on a resource efficiency model explaining how material can be recovered from demolished structures and used in new build projects.
The protocol can be found on the ICE website here.
Best practice in demolition should take into consideration all the possibilities of diverting waste from landfill including the reclamation, re-use and recycling of waste. A pre-demolition audit should be undertaken to identify the type, quantity and recovery potential for the materials present.
More information on the reuse of materials can be found in the Materials module.
