Construction projects—unfixed materials
Construction projects—unfixed materials

The following Construction guidance note provides comprehensive and up to date legal information covering:

  • Construction projects—unfixed materials
  • Materials on site—JCT contracts
  • Materials off site—JCT contracts
  • Unfixed materials in NEC contracts
  • What happens in practice

This Practice Note explains the principles relating to unfixed materials on construction projects and the rules relating to their inclusion in interim payments. It looks at the approach in the JCT and NEC contracts. For an introduction to interim payments generally and the rules relating to them, see Practice Note: Interim payments in construction contracts.

The main purpose of making interim payments is to avoid the contractor having to wait until the works are completed before receiving payment. A contractor is paid for the work it completes as the work progresses and these payments allow it to fund future purchases of labour, materials and plant in order to complete the remainder of the works. Many contractors would be unable to complete a project without receiving interim payments (and where the Housing Grants, Construction and Regeneration Act 1996 applies, construction contracts must provide for interim payments—see Practice Note: Payment in construction contracts under the HGCRA 1996).

In addition to the labour, plant and materials used in the work completed to date, the other main area of expenditure which a contractor will have incurred at the time of a valuation is the purchase of materials before they are included in the works. On many projects certain materials will need to be purchased well ahead of the planned installation date in order to give time for