Design brief
Also called Temporary works design brief
A temporary works design brief is the statement of requirements issued to a temporary works designer before design starts, setting out what the temporary works has to do, the loads and constraints it must accommodate, the site conditions assumed, and the design parameters to be used. The brief is the input to the design; the design check is the scrutiny applied afterwards.
In practice
For crane matting the brief is where the ground figure has to be stated, and it is where it is most often left blank. A brief giving the outrigger reactions from the load chart, the crane configuration and set-up position, and the allowable ground bearing pressure with its source, produces a design that can be checked. A brief giving the crane and leaving the ground to be assumed produces a design in which the most important number was chosen by the designer with no site information — and it will still look like a finished design.
Where this comes from: UK contractor practice under a temporary works procedure, of the kind BS 5975-1:2024 gives recommendations for. What a brief has to contain is set by the project’s procedure and by the designer’s own requirements.
Where it matters on site
This is the document a supplier should ask to see, and the one worth pushing back on. We can state what a configuration is — its plan area, its published safe working load, its build-up and its weight — and our crane mat calculator matches those specifications against a stated reaction. What no supplier can provide is the ground half of the brief: the allowable bearing pressure at the set-up position, and where it was established. Where that figure has not been established, saying so in the brief is the correct entry, and your temporary works designer decides what to do about it.