The design brief is the statement of what you need the temporary works to do. It is the instruction from the project to the designer, and everything downstream — the design, the check, the permit, the inspection regime — inherits whatever quality it has.
It is also the most commonly skipped document in the whole process. A phone call and a marked-up drawing is not a brief, and when the scheme comes back over-engineered, late, or built on assumptions nobody agreed to, the brief is almost always where it went wrong.
What the brief is actually for
A designer can only design against what they have been told. Where information is missing they have two options: ask for it, or make a conservative assumption. Asking costs programme time. Assuming costs money, because a conservative assumption on loads or ground conditions produces a heavier, more expensive scheme than the situation requires.
A good brief therefore does two jobs at once. It removes the need to assume, and it creates a written record of what was agreed — which matters a great deal when the sequence changes three months later and someone needs to establish whether the design still holds.
What to include
The list below covers what a designer typically needs. Not every item applies to every scheme, and a brief for a simple propping arrangement should be short. But each omission should be a decision, not an oversight.
Design brief contents
- Project name, location and the temporary works register reference for the item
- A clear description of what is required and, importantly, why — the problem being solved, not just the solution someone has in mind
- Design life and the period the temporary works will be in place
- All imposed loads: material storage, plant, personnel, stacked loads, concrete pressures
- Environmental loading: wind, water, surcharge, thermal effects where relevant
- Ground conditions, including any site investigation data, and bearing capacity where known
- Information on the existing or permanent structure, including drawings, revisions and any known capacity limits
- The construction sequence, and any part of it the temporary works must accommodate
- Site constraints: access, headroom, working space, exclusion zones, adjacent structures, buried and overhead services
- Interfaces with other temporary works, other trades or other designers
- The design category and the checking arrangements that follow from it
- Applicable standards and any client-specific procedure requirements
- Deliverables required: drawings, calculations, method statement input, design check certificate
- The required date, and what it is driven by
- How residual risks should be communicated for site implementation
Who prepares it
The Temporary Works Co-ordinator usually compiles the brief, drawing on the project team for the information they hold — the engineer for loads and sequence, the works manager for access and constraints, the permanent works designer for structural capacity.
The designer is entitled to challenge a brief that is incomplete, and a good one will. If a designer accepts a brief with no stated loads and no sequence without asking a single question, that is a warning sign about the design you are going to receive.
The design category belongs in the brief
The category determines who is allowed to check the design, ranging from a colleague in the same team through to an engineer in an entirely separate organisation. Setting it at the brief stage rather than after the design is complete avoids the situation where a scheme turns out to need independent external checking that nobody budgeted for or programmed.
Under-categorising is one of the most common temporary works audit findings. It usually happens for programme reasons rather than dishonest ones, but the effect is the same: a scheme that warranted genuine independence was checked by someone who sat next to the designer.
If there is any doubt about the category, resolve it before the design starts. Recategorising afterwards means recommissioning the check, which costs far more time than getting it right at the brief.
The gaps that cause the most trouble
Frequent omissions
- No design life stated, so a scheme intended for three weeks is designed — or not designed — for eighteen months of exposure
- Loads described as "normal construction loading" rather than quantified
- No construction sequence, so the designer cannot tell which load cases are simultaneous
- Capacity of the existing structure unknown, forcing a conservative assumption that triggers unnecessary backpropping
- Ground conditions omitted entirely on schemes bearing directly on ground
- Design category not stated, so the checking arrangements are decided late
- Required date driven by when someone noticed, rather than by the programme
- No mention of interfaces, so two designers each assume the other is dealing with the connection between their schemes
Change control after the brief
Briefs go out of date. Sequences change, plant gets substituted, a crane moves, an excavation goes deeper than planned. Each of those may invalidate an assumption in the design.
The discipline that matters here is simple: when something changes, the brief is revised and reissued, the design is reviewed against it, and if the design changes then the check is repeated and the revision number moves. Skipping that loop is how sites end up with temporary works built to a superseded drawing while the permit references a revision that no longer describes what is standing there.