A fixed-price building quote is an offer to carry out one defined scope of works for one stated sum. The price is fixed against that scope — not against the building. So what actually holds the number is three things written down: the scope you have described, the exclusions you have named, and the assumptions you have priced on. Everything that can change a fixed price later runs through one of those three.
Clients hear “fixed price” as “this is what the job will cost me”. You mean “this is what those works cost at those quantities and that specification”. Both readings are reasonable, which is exactly why the gap between them turns into a dispute at the final account. Close it in the document rather than in a conversation on site: describe the works, measure them, and state what sits outside. A quote that a client can check line by line is also the quote you can defend when they ask why a variation costs what it costs. If you are still deciding what belongs in the document at all, start with what a builder's quote should include →
Our free construction quote template has separate sections for all three, so the exclusions and assumptions are somewhere the client reads rather than something you remember to mention.
The client changes their mind, or the architect issues a revised drawing. Price the difference before the work happens and get it agreed in writing. A variations clause that says how changes will be valued is what turns an argument into an arithmetic exercise.
Work you know is coming but cannot yet measure — a drainage connection whose route is unknown, a beam the engineer has not sized. Show it as its own visible line, say what it assumes, and state that it is adjusted against measured work. Hidden inside a rate, it looks fixed and behaves otherwise.
What is under the slab and behind the plaster is the largest single risk in domestic work, and no amount of pricing skill removes it. Name the condition you have assumed, exclude the condition you have not seen, and the fixed price survives the opening-up.
A fixed price is an offer for its stated validity period. Once that date passes, re-price the work against current material and labour costs rather than applying an unexplained uplift. If the client accepts within the period, the agreed scope stays at the accepted price.
Every fixed price allocates risk, whether or not it says so. The instinct is to cover the unknowns by lifting the rates, but a padded rate loses you the jobs you would have won and still does not cover the one thing that actually goes wrong. The alternative is to be explicit: carry the risks you can size, put the ones you cannot into a named exclusion or a labelled provisional sum, and let the client see which is which. Clients rarely object to a risk being named. They object to discovering it after they have signed.
Some jobs cannot honestly be fixed, and pretending otherwise costs more than declining to. Works where the scope genuinely is not known until you open up — a full strip-out, a damp or structural repair, a listed building where the method depends on what is found. A drawing set that is planning-only, with no specification and no engineer's details. A client still changing their mind about layout. In those cases quote what can be fixed, price the unknown part as a provisional sum or a measured rate against actual work, and say plainly which is which. An estimate you have labelled honestly is worth more than a fixed price you will have to walk back.
Send the drawings and QuoteWise returns a measured, sectioned bill with every quantity, rate and assumption visible. That is a working draft, not a fixed price — and the difference matters. You check the quantities against the drawings, correct the rates to your own, decide which of the risks above you are prepared to carry, then set the exclusions, the provisional sums and the validity period yourself before anything goes out under your name. Fixing a price is a commercial decision only you can make. The take-off is the part being handed to you.
It is an offer to carry out one defined scope of works for one stated sum, rather than to charge for whatever the job turns out to need. The price is fixed against that scope — not against the building. Which means the scope description, the exclusions and the assumptions are what hold the number: change any of them and you are into a variation rather than the original price.
Anything you cannot see, cannot price honestly, or do not control. Statutory fees such as planning and Building Regulations charges, party wall awards, structural engineer's fees, asbestos removal, unforeseen ground conditions, and works to services you have not been able to inspect. Write each one as "no allowance" with a short reason, never as a zero-pound line — a zero reads as included at no cost.
Not the accepted scope at the accepted price — that is the point of quoting rather than estimating. What you can do is price the difference when the scope changes, which is why the quote needs a variations clause saying that instructed changes and named excluded risks are charged separately, and how they will be valued. Agree each variation in writing before the work happens, not at the final account.
A provisional sum is an allowance for work you know is coming but cannot yet measure — a drainage connection whose route is unknown, a beam whose size the engineer has not confirmed. Show it as its own visible line labelled provisional, state what it covers and what it assumes, and make clear it is adjusted against actual measured work. A hidden provisional sum inside a rate looks like a fixed price and behaves like an open one.
Long enough for the client to decide and short enough that material prices have not moved under you — a stated validity period on the quote is what makes that boundary real. Say what happens after it expires: usually a re-price rather than an automatic uplift. An open-ended fixed price transfers every market movement between quoting and starting on site onto your margin.
No. Send the drawings and QuoteWise returns a measured, sectioned bill with every quantity, rate and assumption visible — a working draft, not a fixed price. You check the quantities, correct the rates to your own, decide which risks you are prepared to carry, and set the exclusions and validity before it goes to a client under your name. The fixed price is your commercial decision; the measuring is the part being handed to you. Your first three quotes are free.
Send the drawings and get a measured, sectioned bill back to price from. Your first three quotes are free.