Write the basis of estimate

Record which drawings and revisions you priced, the method and programme you assumed, the ground and access you took for granted, and every gap you filled with a judgement.

理由: The assumptions are where the risk lives. Writing them down turns a silent bet into an agreed position and gives you the ground to stand on when the design that lands is not the one you priced.

Set out plainly what the price includes, what it excludes and the qualifications that condition it, so there is no doubt on either side about what was bought.

理由: Most disputes are not about the rate, they are about whether an item was in or out. A clear inclusions and exclusions list settles that before it becomes a variation argument.

Tie the basis to the bill it explains, so anyone opening the price can read the assumptions that produced it without hunting through email.

理由: A basis that lives apart from the bill gets lost. Kept together, the two travel through review, award and delivery as one story about what was priced and why.

Issue the basis alongside the price in the estimate report, so the client reads the number and the ground it stands on at the same time.

理由: A number sent on its own gets treated as gospel and then disputed. Sent with its basis, it invites the right conversation about scope and risk before anyone commits.