A specification is a document that describes the work to be carried out on a project and the standard of materials and workmanship required.
The specification works alongside the drawings and pricing documents to define what the contractor must deliver. In the UK, many specifications are produced using the NBS system. A specification may be prescriptive, stating exact products, materials and methods, or performance-based, stating the outcome required and leaving the contractor to decide how to achieve it, which is common in design and build. For the quantity surveyor, the specification is essential for accurate measurement and pricing, because the description of each work item depends on it. Points to watch include:
- conflicts between the specification and the drawings
- open items such as “or equivalent” or “to be confirmed”, which carry pricing risk
- changes to the specification after the contract is let, which may be variations
Related terms: scope, employer’s requirements, drawings, bill of quantities.
