The four things builders leave out of a quote

Three builders quote for the same job. One comes back several thousand pounds cheaper than the other two.

Nine times out of ten that gap isn’t efficiency, a better supplier deal or sharper pencils. It’s scope. Something is missing from the cheap one, and you won’t find out which until the work is underway and it arrives as a variation — at which point you have a half-built extension and no leverage at all.

Here’s what’s usually missing.

1. Making good

The extension itself gets priced. What doesn’t is putting the existing house back together around it:

Re-plastering where the old external wall came out
Matching floor levels between old and new
Moving radiators that are now in the middle of a through-room
Decorating the rooms of the existing house that got opened up

It isn’t glamorous and it isn’t optional. It’s also several thousand pounds of labour and materials that has to be paid by somebody.

Ask: “Does this include making good and decorating the existing rooms?”

2. External works

The garden after the digger has been through it.

Patio, levels, turf, the path down the side that got destroyed, the fence panel that came out for access. On a sloping plot you can add retaining and drainage to that list, which is a serious cost in its own right and nothing to do with the extension.

Plenty of quotes stop at the back door. The job doesn’t.

Ask: “Is reinstating the garden and the access route in this price?”

3. Provisional sums presented as fixed

This is the one that costs the most and is hardest to spot.

Foundations are the obvious example. Nobody knows how deep they need to go until the hole is dug — a tree within influencing distance, made ground, or a shallow neighbouring footing all change the answer. An honest quote states foundations as a provisional sum and says so.

A quote that gives you a single confident number for foundations without anyone having dug a trial hole isn’t more accurate than the honest one. It’s the same uncertainty, hidden, and you’ll pay the difference as a variation.

Drainage is the same story. If a shared sewer runs under the footprint you need a build-over agreement with the water authority and possibly a new manhole. That takes weeks of calendar time as well as money.

Ask: “Which lines here are provisional sums, and what happens if they come in over?”

4. Skips, scaffolding and welfare

Individually small. Across a twelve-week job, thousands of pounds.

Skips and their exchanges, scaffolding hire and adaptations, temporary welfare, site power, a temporary loo. Every job needs them and they appear on some quotes and not others.

Ask: “Are skips, scaffolding and site setup included?”

How to compare three quotes properly

Don’t compare the totals. Compare the scope, then the totals.

Write the four items above down the side of a page. Mark each quote in or out for each one. This alone usually explains the gap.
Find every provisional sum in each quote and ask what happens if it’s exceeded.
Ask what’s explicitly excluded. A good quote has an exclusions list. If a builder can’t tell you what they’re not doing, they haven’t thought about it properly.
Ask for a programme, not just a price. A start date, a completion date and the stages in between. A builder who won’t commit to dates in writing has told you something useful.
Ask how variations are handled. The right answer is: priced in writing and agreed by you before the work happens. Not added to the final bill.

Why we quote the way we do

Every line priced. Provisional sums labelled as provisional, with the reason. Exclusions stated plainly. Making good, external works and site setup all in the number rather than lurking outside it.

It occasionally makes us look more expensive on first read than a builder who has left three of those out. We’d rather have that conversation up front than the other one on week nine.

If you’ve got quotes in front of you and you’re not sure how to read them, send them over — we’ll tell you what’s missing, even if you don’t end up using us.