One fixed price for the whole job — not the hours

Loft Conversion Fair Price

Typical trade: loft conversion specialist / builder. Move the sliders and answer the questions.

Describe the job or snap a photo — AI fills in the sizes

Conversion type
Add an en-suite?

Fair fixed price for the whole job

£56,500

Fair range: £49,720 – £66,670

25 m² dormer loft

Realistic time on site

32.4 days

Crew / total hours

3 · 730.0 h

Labour (730.0 h × £40)
£29,200
Materials
£23,000
Structural engineer & drawings
£1,800
Building control
£900
Scaffolding
£1,600

Over £83,338? Ask why in writing.

  • No structural calculations for steels
  • Fire-escape route (protected stairway) not mentioned
  • Quote excludes stairs

Insist on

  • One written fixed price for the full scope — no open-ended hours.
  • Deposit of 10–20% at most; balance after you inspect the work.
  • Any extra work agreed and priced in writing before it starts.
  • A rear dormer usually takes 6–8 weeks; Velux-only 4–5 weeks.
  • Party wall notices may be needed on terraced/semi houses.

Estimate for an experienced, insured tradesperson. Local prices vary — adjust the hourly rate for your area.

Calcurly.com area calculator showing dimensions, result, and cost breakdown

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About this calculator

Realistic weeks and fixed price for a Velux, dormer or hip-to-gable loft conversion. Answer a few questions, move the sliders, and get a brutally realistic time on site plus one fixed price for the whole job — so you can insist on a total rather than open-ended hours. Tradespeople can use it to quote fairly.

Frequently asked questions

How long should this job really take?
The calculator shows realistic on-site hours for an experienced, insured tradesperson working at a normal pace. Quotes far above the upper range deserve a written explanation.
Should I pay by the hour or a fixed price?
Agree a fixed written price for a clearly defined scope. Pay a small deposit (10–20% at most), staged payments on larger jobs, and the balance only after you have inspected the finished work.
What does the Loft Conversion Fair Price do?
Realistic weeks and fixed price for a Velux, dormer or hip-to-gable loft conversion. Realistic weeks and fixed price for a Velux, dormer or hip-to-gable loft conversion. Answer a few questions, move the sliders, and get a brutally realistic time on site plus one fixed price for the whole job — so you can insist on a total rather than open-ended hours. Tradespeople can use it to quote fairly.
Is the Loft Conversion Fair Price free to use?
Yes. Every calculator on Calcurly.com is free, works in your browser without sign-up, and can be embedded on your own website.
How accurate is the Loft Conversion Fair Price?
Results are calculated in real time using industry-standard formulas. Treat the output as a well-informed estimate — always cross-check with local regulations, product datasheets, or a qualified fair price home jobs professional before committing to a purchase or a job.
Can I embed the Loft Conversion Fair Price on my own website?
Yes — copy the iframe snippet at the bottom of this page, or use the Embed Generator to customise the size. The embedded version stays in sync with the live calculator on Calcurly.com.

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