The following pages detail construction and design solutions that reduce waste generation in the development process. These solutions should be read in conjunction with the guidance contained in the materials module. Most approaches are relevant to all types of site.
For more information on many of the solutions described in this section go to Hertfordshire Waste Aware website and the national Waste and Resources Action Programme (WRAP) site.
Use of pre-cast/pre-fabricated materials and modular construction
Pre-fabricated and modular components (e.g. pre-cast concrete beams, insulated wall panels, bathroom pods) reduce the amount of waste generated as they typically eliminate the most labour intensive (and wasteful) processes. In the case of modular construction, standardised components and repeat construction processes are also pursued, which typically lead to less generation of waste.
By using alternative design solutions, the quantity of materials required can be reduced, which in turn will reduce the quantity of wastage. Alternative design solutions might also remove the need to undertake on site activities that produce waste.
To support design teams, WRAP have published a guidance document explaining how to ‘design out’ construction waste. The document contains five principles:
- Design for reuse and recovery.
- Design for off site construction.
- Design for materials optimisation.
- Design for waste efficient procurement.
- Design for deconstruction and flexibility.
WRAP have also created a Designing out Waste Tool for Buildings (DoWT-B), which is an online options appraisal tool to indicate the opportunities to ‘design out waste’. The DoWT-B provides an overview of the value of the materials typically consumed and wasted and investigates the benefit of waste reduction actions.
Flexibility in design reduces the need for major refurbishments and gives the building a longer life span by ensuring that buildings readily accommodate new functions, (without requiring demolition and creation of new structures), thus eliminating the waste generation process. Examples of flexible design include:
- Ceiling heights that accommodate changes of room use and associated servicing requirements.
- Use of non-load bearing partitions.
Specification of materials with a recycled content
Materials with a recycled content incorporate a particular level of waste during manufacturing, the waste being post-consumer or pre-consumer. Many product manufacturers incorporate a high level of waste into the manufacturing process and create products that present the same performance and cost as materials with no recycled content. Consideration should also be given to the use of reclaimed materials.
Allocation of appropriate recycling storage facilities
Recycling is facilitated by providing sufficient space, whether for domestic kerbside collection boxes and composting facilities, or larger commercial waste recycling facilities.
Hertfordshire County Council offers discounted home compost bins to Hertfordshire residents. More information on this and other waste initiatives can be found at Waste Aware.
In larger residential buildings, and non domestic buildings, waste and recycling storage areas should be designed in and the design layout must demonstrate adequate space to facilitate waste recycling through separation, storage, handling, bulking and collection of waste generated within the property.
If a BREEAM certificate is being sought then the technical guidance for the specific scheme should be reviewed as there might be credits available for recycling storage facilities. New developments should be flexible enough to accommodate different collection systems and the potential for future changes.
In particular, full consideration should be given to:
- The location and design of facilities to ensure minimal visual impact and full integration into the scheme design.
- Access to ensure waste containers can be easily accessed (and moved) by development occupiers and local authority/private waste contractors.
- Safety to ensure that bins do not obstruct pedestrian, cyclist or driver sight lines.
- Provision of facilities for composting household waste.
30% of household waste can be composted (70% of total organic waste)
A number of Hertfordshire local authorities have produced detailed advice notes on the storage of refuse at residential developments.
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 BREEAM certification. Best practice guidance KPIs and guidance on how to use them can be found at KPIzone and BRE SiteSmart.
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 SMART Waste Plan which is a SWMP web-based tool with an integrated measurement function. Further information can be found on the WRAP website.
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:
|Broken brick or concrete
||On-site levelling or filling holes
||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:
*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.
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, visit to the Environment Agency website.
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 nd reused.
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.
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.
Operational waste management
The effectiveness of building operational waste management is largely dependant on the willingness of the building occupants to actively manage waste. However, as detailed earlier, sustainable operational waste management can be actively encouraged through design. Notably by providing suitable designed and located waste storage facilities, and linking up with Hertfordshire’s recycling schemes.
Further information on operational waste management and the schemes available to Hertfordshire residents, employers, etc can be found at Waste Aware.