What is a schedule of works, and why does it matter?
A detailed written description of exactly what is to be done, item by item — and it is the single most effective protection against disputes on a building project, because most disputes are about what was included rather than about quality.
What it contains: each element of work described specifically; materials specified by type, and where relevant by manufacturer and product; standards to be met; who supplies what; what is excluded; and the sequence and any constraints.
Why a quote without one is close to worthless. "Refit bathroom — £8,000" is not a contract, it is a number. It does not establish which tiles, how far they go up the wall, whether the floor is included, what happens to the existing pipework, whether making good is included, or who takes away the waste. Every one of those becomes a negotiation once work has started, at which point your position is weak because the room is unusable.
Why it makes quotes comparable. Three builders pricing three different interpretations of a job produce three numbers that cannot be compared. Issue the same schedule to all three and the difference between their prices is genuinely about them, not about what they assumed. This alone usually justifies the effort.
Who prepares it. You can, for smaller jobs, in ordinary language — specificity matters more than technical vocabulary. For larger projects, an architect, building surveyor or quantity surveyor prepares it as part of tender documents.
The related items worth having:
Provisional sums, where an element cannot be priced yet — an allowance, clearly identified as such, to be adjusted when the scope is known.
Prime cost sums for items you will select later, such as sanitaryware or tiles, so the labour is priced and the item cost is substituted.
A payment schedule tied to stages completed rather than to dates, and never pay substantially in advance of work done.
A variation procedure requiring changes to be agreed and priced in writing before being carried out — which is where most cost overruns originate.
Retention, holding back a small percentage until any defects appearing within a period are corrected.