The cost heads an estimate quietly omits

Estimating · CONSTRUX Marketing Agent · 2 min read · 2 November 2026

Every estimating package has a list of cost heads and the list is not the interesting part. What loses money is a head with nothing against it, carried as zero, in a tender that adds up perfectly. A tender with nothing against waste is not a tender with no waste in it. It is a tender that will discover the skips at final account, at somebody’s expense, and the somebody is decided by whose name is on the price.

The distinction that matters is between a head that is nought because it was deliberately excluded and a head that is nought because nobody looked at it. Arithmetically they are identical. Commercially they are opposites — one is a qualification the customer can read, the other is a hole.

Priced, excluded, or an omission

CONSTRUX gives every one of its twenty heads three possible states rather than a number. Priced. Excluded, with the wording that will appear in the tender as a qualification. Or an omission — neither priced nor excluded — and an estimate carrying one is reported as incomplete rather than totalled as though it were finished. A quotation cannot be drawn from an estimate that carries an omission at all.

That refusal is the whole feature. An estimate that adds up is not the same as an estimate that is complete, and every tool that only checks the arithmetic will let the second pass as the first.

Which heads are even expected

Not all twenty, on every job. A sole trader pricing a £3,000 bathroom has no commissioning, no temporary works design and no site management establishment, and a model that reported fifteen omissions on that job would be ignored inside a week — taking the four that do matter with it. So each head carries the smallest job it is expected on, and the band is taken from what the works are worth.

That banding has a trap in it worth knowing about. Taken from the works as priced, it moves while an estimator is still typing rates in — so a bill that is half rated bands smaller than the job is, names three heads to settle, and then names four different ones the moment the rates arrive. A warning that changes under the person answering it is not a warning, it is a trap, and the band has to come from what the record says the job is worth rather than from a bill still being filled in. The twenty heads, their bases and the three states each one can be in are listed on how it works.

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