Descriptive information is the means by which the design team describes a building system or component in enough detail for a specialist subcontractor to complete its design.
It typically takes the form of performance specifications, outline drawings and design intent information, setting out what the system must achieve rather than exactly how it is to be built. The specialist then develops it into construction information. Descriptive information is common for systems such as curtain walling, lifts, sprinklers and some mechanical and electrical installations. For the QS, pricing from descriptive information carries more uncertainty than pricing from prescriptive information, so specialist input and suitable risk allowances are usually needed.
- Check that responsibility for design is clearly allocated in the contract.
- Interfaces between specialist designed systems are a frequent source of risk.
Related terms: prescriptive information, construction information, contractor’s design portion, performance specification.
