Loft Conversion Cost Calculator
A realistic build-cost estimate for a rooflight, dormer or hip-to-gable loft — honest ranges, no lowball number to get you on the phone.
- Dormer (25m² × £2,000)
- £50,000
- Contingency (15%)
- £7,500
- Estimated build cost
- £57,500
+ our design fee
We don't charge a percentage of the build — it's a fixed fee, agreed with you up front. Book a free call and we'll confirm the exact figure for your loft.
A rough guide to build cost only. Structural work, stairs, roof condition and access all move the number — your design fee is quoted separately and is always fixed.
Planning an extension instead? Try the extension budget planner. Not sure which one you need? See what a loft conversion involves.
Not sure whether to build, wait or move?
That's exactly what the call is for. We'll be straight with you — no pressure, no jargon, no nasty surprises.