What should be in a builder's quotation

A quotation is not a price. It is the document you and your builder will both point at if the job goes sideways, and the only record of what you each thought you had agreed. Most disputes on domestic building work are not about dishonesty; they are about two people holding different pictures of the same job, and a thin quote is what let that happen.

Here is what a quotation should contain.

An estimate and a quotation are different documents

Worth getting straight first, because the words get used interchangeably and they do not mean the same thing.

An estimate is an educated guess. It is not binding, and the final figure can reasonably differ.

A quotation is an offer to do defined work for a defined price. Once you accept it, it forms the contract.

If you are not sure which you have been given, ask. A document headed “estimate” that you have treated as a fixed price is the single most common route into a disagreement about money.

The scope: what is being built

The scope should describe the work in enough detail that a third party could read it and know what was supposed to happen. Not “build rear extension” — dimensions, what it is built of, what the roof is, what the openings are.

Where drawings exist, the quote should reference them by number and revision. “As per drawing 104 rev C” is precise. “As per drawings” is not, and matters the moment there is a rev D.

The exclusions: what is not

This is the section that tells you most about the builder, and the one most often missing. Everything a quote does not include is something you will pay for later, so it should be written down where you can see it.

Common and legitimate exclusions on a domestic job:

• Kitchen units, worktops and appliances
• Sanitaryware, brassware, tiles — or the supply of them where you are choosing
• Floor coverings
• Decoration
• Planning and building control fees
• Structural engineer’s fees
• Party wall surveyor’s fees
• Connections or diversions requiring the water authority or a utility

None of these are red flags. A quote with no exclusions section at all is, because the exclusions still exist — they just have not been said.

Provisional sums and where they will land

Some things genuinely cannot be priced from a drawing. Nobody knows what the ground is like until it is opened, or what state a roof structure is in until the ceiling comes down.

The honest way to handle that is a provisional sum: a labelled placeholder with a figure attached, to be replaced by the real cost when the real cost is known. What you want to see is:

• That it is clearly marked as provisional, not buried in the total
• What it covers
• How it gets settled — measured on site, agreed before the work proceeds

An unlabelled guess is the problem. A labelled one is a builder telling you where the uncertainty is.

The price, and whether VAT is in it

The total should state plainly whether VAT is included or excluded, and at what rate. On a £60,000 job that is a £12,000 question.

Most domestic building work is standard-rated at 20%. There are reduced and zero rates for some situations — certain conversions, some work on properties empty for two years or more, some work for disabled people. If you think your project might qualify, raise it early; it changes the number materially and is not something to discover at the end. HMRC’s VAT Notice 708 is the reference, and it is worth a conversation with your accountant rather than relying on either of us to interpret it.

A payment schedule tied to work, not dates

Payments should be triggered by things existing, not by the calendar. On an extension a sensible schedule might run: on start, on completion of foundations, on completion of the shell, on the roof being watertight, on first fix, on plastering, on completion.

Two things to look at:

The deposit. A modest one to cover materials ordered up front is normal. A large one before anything happens, on the other hand, means you are funding the job rather than buying it — and if the builder disappears, you are an unsecured creditor.

A retention. Holding back a small percentage for a period after completion, released once snagging is done, is common on larger work. It gives everyone a reason to finish the last five per cent, which is the part that most often drags.

Who is responsible for the permissions

The quote should say who is arranging planning permission, who is dealing with building control, who is serving party wall notices, and who is paying the fees in each case. This is not a detail. Building control approval and party wall notices both have to happen before certain work starts, and “I assumed you were doing it” is an expensive sentence in week three.

Variations: how a change gets priced

You will change something. Everyone does. What matters is that the mechanism is agreed before you need it: changes priced and agreed in writing before the work is done, not totted up and presented at the end.

If your quote says nothing about variations, agree that in writing before you start. It is the single cheapest piece of admin on the whole project.

Insurance and guarantees

Ask what public liability cover is held and for how much, and ask for the certificate rather than the number. Ask whether the workmanship is guaranteed, for how long, and what that guarantee actually covers — workmanship and manufacturer warranties are different things.

Ask, too, whether any part of the work is notifiable and who is certifying it. Electrical work in a domestic property is covered by Part P of the building regulations and either needs a registered electrician who can self-certify or a building control application. The same principle applies to gas work and Gas Safe registration. These are checkable on public registers, which makes them worth more than most claims a builder can make.

What to do next

If you have a quotation in front of you and it is missing something on this list, the fix is a straightforward email: ask for the exclusions in writing, ask which sums are provisional, and ask what happens when something changes. A builder who answers those clearly is showing you how the next three months will go.

If you would rather start from a quote that already has all of it, send us the details.