Client's guide to cutting waste from construction projects

Reduce construction wastage allowances and rates


When construction materials are ordered, it is normal practice to add wastage allowances. To reduce wastage allowances, you should instruct the design team and contractor (in the tender and appointment documents) to plan how they will reduce the likely wastage rate through better site practice.

Close co-operation between designers and contractors can reduce wastage rates by identifying potential issues at the design stage.

To reduce wastage rates, you should:

  • set a requirement for a waste reduction target in the project brief and when appointing the design team and contractor
  • ask your design team to reduce the number of different types of materials to be used in the specifications - the fewer types of materials required, the smaller the waste allowance needed
  • identify which materials offer the biggest potential waste and cost savings by reducing wastage allowances to good practice levels
  • ask your main contractor to discuss wastage allowances before agreeing tender prices with trade and sub-contractors
  • monitor waste streams during the project to compare actual wastage rates with the agreed allowance

Wastage rates in small projects

Small projects can limit some of the opportunities to reduce costs. However, clients can still achieve cost savings by:

  • identifying the top materials contributing to waste
  • discussing with contractors what wastage rates they anticipate on these materials and how these could be minimised
  • identifying actions to reduce waste
  • checking actual wastage rates by inspecting skips or skip data

For more information, see how to cut waste from smaller projects.