Costs & Budgeting
Why building quotes vary so much for the same project
Why two quotes for what looks like the same job can differ by tens of thousands of pounds.
Quotes for the same brief often vary because they're not actually quoting the same scope - one may exclude items (fittings, waste removal, making good) that another includes, use a provisional sum where another gives a fixed price, or price a different specification. The way to compare fairly is to ask each quote to itemise exactly what's included, not just look at the bottom line.
Last updated 20 August 2026
Scope, not just price
The single biggest reason quotes vary is that they aren't pricing the same thing. One quote might include kitchen fittings, flooring and decorating; another might price the structural shell only and leave the rest as a separate cost. Read what's actually included before comparing the totals.
Fixed price versus provisional sum
A provisional sum is an estimated allowance for something that isn't fully specified yet - a kitchen budget, for instance, before you've chosen units. A quote built on generous provisional sums can look lower up front and cost more once those items are actually specified. Ask which figures are fixed and which are provisional.
Specification and quality tier
Structural work priced to different standards, different glazing specifications, and different finish quality all produce genuinely different (not just differently-marked-up) costs. A lower quote sometimes reflects a lower specification, which is a legitimate choice as long as it's a deliberate one.
What to actually ask for
Ask each quote for a like-for-like breakdown: what's fixed, what's provisional, what's excluded, and what the payment schedule looks like. That's what makes quotes genuinely comparable, rather than comparing three different scopes dressed up as three prices for the same job.
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