How to Compare Builder Quotes Without Getting Stung

The problem

You ask three builders to quote the same job. One comes back at £52,000, one at £68,000 and one at £91,000. Who's right?

Usually: none of them are comparing the same scope.

Step 1 — Force a like-for-like scope

Before quoting, send every builder the same one-page spec:

• Drawings (even rough sketches)
• Finish level for kitchen, bathroom, flooring
• Who supplies what (you vs. them)
• Decision dates and start window

If you don't pin the scope, you're comparing three different jobs.

Step 2 — Break every quote into the same 8 buckets

1. Prelims (scaffold, skips, welfare, insurance)
2. Demolition & strip-out
3. Groundworks & foundations
4. Structure (steels, masonry, timber)
5. Roof & envelope
6. First fix (plumbing, electrics, plastering)
7. Second fix (kitchen, bathroom, finishes)
8. Externals & making good

Lay them side-by-side in a spreadsheet. The gaps jump out immediately.

Step 3 — Hunt for what's missing

The cheapest quote is almost always missing something. Common culprits:

• VAT (always ask if VAT is included)
• PC sums set artificially low for kitchen, bathroom, tiles, sanitaryware
• Foundations "subject to dig"
• Making good after the works
• Building control sign-off

Step 4 — Run the independent number

Plug your project into the Build Price IQ cost checker for a 2026 market median. If all three quotes are below the median, one of them is wrong. If all three are above, your spec is pricier than you think.

Step 5 — Pick on more than price

Once quotes are normalised, choose based on:

• Recent comparable work (photos + references)
• Cashflow profile (deposit, stage payments)
• How they handle variations in writing
• Whether they answered your questions properly

The cheapest quote that's missing 15% of the scope is the most expensive quote.