How much will your extension really cost?
Your initial estimate says £80k - Your builders quotes £128k.
You end up spending £192k.
That gap between what you were told and what you actually paid is where homeowners lose £50,000–£100,000 on renovations they thought they could afford.
Build|Lens closes that gap before you spend a penny.
Real construction costs from completed UK project invoices as well as daily updated market data for materials costs and labour costs covering rear extensions, loft conversions, renovations, for every residential project type in the UK.
Our data is different.
Why the number matters more than the house
Eight in ten renovation projects exceed their original budget.
The gap between what a project is expected to cost and what it actually costs routinely runs into six figures.
Whether it is a rear extension in London, a loft conversion in Manchester, or a full renovation of a Victorian terrace in Hull; the gap between estimate and reality is consistent and predictable.
Build|Lens exists to close it.
Our Data is Different
Independent construction cost intelligence
Built on live data sets of completed UK residential project invoices with live updated merchant and labour pricing.
Not estimates, not industry averages — real final accounts from real builds, actually invoiced, actually paid.
Every property type, every situation
Victorian terraces to new-builds. Rear extensions to full renovations.
Buying a house that needs work?
Checking a builder's quote?
Or trying to understand why your house is not selling.
Property-specific, delivered in 24–48 hours
Postcode-calibrated cost analysis delivered to your inbox.
No site visit required.
Works with architect plans, estate agent floor plans, or hand-drawn sketches.
Eight Market Intelligence reports from £49
From a quick extend-or-move decision at £49.
To a full tender-ready cost intelligence report at £975.
Independent cost data & analysis, not interested opinion.