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The use of recycled & secondary materials in residential construction (NF45)


The use of recycled and secondary materials as aggregates in construction for applications such as pipe bedding and concreting aggregate is increasing, with current estimates indicating that up to 25% of construction aggregates come from recycled and secondary sources. Their use supports the Government’s sustainability agenda and gives developers credits for use of recycled content in construction projects.Interestingly, the UK has the highest proportion of aggregate demand met from recycled and secondary aggregates in the EU, with further increases predicted in the future.

This guide describes how to source, correctly specify and use secondary and recycled materials in residential construction (illustrated by case studies and examples). It also provides key information on how to avoid incorrect use (and consequent unsatisfactory performance) of these materials.

Summary of content

There is a great deal of interest in the construction sector, and from their clients, in the greater use of recycled and secondary materials for construction.  This guide, which is targeted mainly at developers, specifiers and contractors across the construction residential sector, can be used to:

  • Gain an overview of recycled and secondary aggregates, their benefits and applications.
  • Find out how to obtain and specify recycled and secondary aggregates.
  • Avoid common pitfalls in choice and use of aggregate materials.
  • Access case studies and examples of the proper (and some inappropriate) uses of aggregates in residential construction.
  • Identify key written resources and information.
  • Gain awareness of low carbon cements and the main cement replacement materials available for use in concrete.

The use of recycled and secondary aggregates in a range of construction applications within the perimeter of residential properties (including driveways) provides the main focus for this guide.  Related applications such as estate roads, utilities and shared car parking areas are not covered in detail although many of the principles covered here will still apply.

This guide includes highly detailed technical information which will mainly be of interest to large specifiers and developers.  Useful resources on recycled aggregates (that are more specifically targeted at small and medium-sized businesses), are provided by Business Link via their website.  Opportunities to use low carbon cements and cement replacement materials are briefly reviewed in Appendix G.

Other (non-mineral-based) construction materials or products such as recycled plastics, cellulose fibre insulation made from, for example, recycled newspaper are outside the scope of this guidance.  However, the WRAP reference guide Opportunities to Use Recycled Materials in House Building gives further information.