Brief Before Budget: Eight Assumptions UK Commercial Teams Should Record Before Tender

Commercial cost surprises rarely begin on site. They usually begin in a brief that was clear enough to start a conversation but not clear enough to price. When a tender is issued with unresolved assumptions, each bidder resolves them differently. The lowest price may simply be the one that made the most generous assumption. The result is not necessarily poor delivery; it is a commercial baseline that was never stable.

At SEH Ltd, the practical remedy is not a longer brief for its own sake. It is a short, disciplined audit of the assumptions that carry the greatest financial weight. Before pricing starts, the client and project team should be able to point to a written position on each of the eight items below. Where the position is still to be confirmed, it should be recorded as a risk with an owner, not left to interpretation.

1. The boundary of the works

Define what is included by scope, location, system and deliverable. A phrase such as 'complete electrical installation' may feel clear in a meeting, but it leaves room for disagreement over containment, final connections, testing, labelling and commissioning support. The brief should state where the work starts, where it ends and what handover evidence is expected.

2. Exclusions that are genuinely understood

Exclusions are not a footnote. They are part of the commercial offer. If builders' work, temporary services, access equipment, statutory approvals or out-of-hours working are excluded, the brief should say who carries them and how they interface with the priced scope. An exclusion without a counterpart is simply a gap.

3. Interface ownership

Most commercial projects depend on boundaries between packages. The risk lies in the word 'interface' being used as a description rather than an allocation. For each key interface, name the party responsible for design coordination, installation, testing and acceptance. Mark the information each party must provide and the date by which it is needed.

4. Acceptance criteria

The brief should distinguish between completion and acceptance. Completion may be a practical milestone; acceptance may depend on tests, certificates, witnessing, snagging closure or client sign-off. If the criteria are not written down, the supplier may price to a reasonable standard while the client expects a different one. Both positions can be sincere, and both can be expensive.

5. Information dependencies

Pricing depends on information. The brief should identify the drawings, surveys, specifications, warranties and client decisions that the price assumes. It should also state what happens if those inputs change. A tender priced against an outdated drawing is not necessarily a competitive tender; it is a price waiting to be adjusted.

6. Programme assumptions

A price is tied to a programme, even when the link is not stated. The brief should record assumed start dates, access dates, working hours, sequence constraints and possession of the site. If the programme is indicative, the pricing assumptions should be indicative too. If the client requires a fixed date, the brief should expose the dependencies that make that date achievable.

7. The change mechanism

Every commercial brief should explain how change will be priced before change occurs. That means rates, daywork, validation of instructions, notice periods and the treatment of prolonged or disrupted work. A clear mechanism does not prevent change; it prevents change from becoming a separate negotiation under pressure.

8. Ownership of the assumptions register

An assumption that is not owned is an assumption that will be rediscovered as a dispute. The brief should name the person or role responsible for maintaining the assumptions register, reviewing it at tender clarification and updating it when information changes. The register should be visible to both commercial and delivery teams, not filed away after the tender returns.

The audit in practice

The eight-point audit need not produce a lengthy document. A two-page schedule can be enough if it is specific. Each line should state the assumption, the evidence behind it, the owner and the commercial consequence if it proves wrong. That last column matters. It turns a polite clarification into a decision about risk.

Clients should also resist the temptation to treat every assumption as a reason to delay pricing. The purpose is not to resolve every detail before tender; it is to make the unresolved details visible. A bidder can then price the known scope and identify the cost of the unknown. That is a more honest tender than a single figure built on silent guesses.

For UK commercial teams, the discipline is particularly valuable where design is not fully developed, where multiple packages meet, or where a programme is under pressure. In those conditions, the brief becomes the commercial control point. If it is vague, the market will price that vagueness in different ways. If it is explicit, the market can compete on the same basis.

The lesson is straightforward. Cost control does not begin with the first valuation or the first change instruction. It begins when the brief is written and the assumptions are exposed. A short audit before pricing starts is cheaper than a long explanation after the budget has moved.