Velux Loft Conversion Cost UK 2026

A Velux (rooflight) loft conversion is the cheapest way to convert a UK loft because the roof shape stays the same — you simply insulate, board, light and floor the existing space, then add 2–4 Velux windows. Costs in 2026 sit at £30,000–£55,000 for a typical 25 m² loft.

Quick answer

Typical UK price range: £30,000–£60,000. Typical time: 4–6 weeks.

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Key points

  • Cheapest type of loft conversion at £1,300–£1,800 per m²
  • Permitted development for nearly all UK semis and terraces (no planning permission)
  • Needs at least 2.3 m existing ridge height for usable space
  • Each Velux window adds £900–£1,800 fitted

Cost breakdown

Item Low High
Structural works (joists, trimmers) £4,500 £9,000
Insulation, plasterboard, plastering £3,500 £6,000
Velux windows (3 typical) £2,700 £5,400
Staircase + flooring £3,500 £6,000
Electrics + radiators £2,000 £4,000
Architect + building control £2,500 £4,500

Cost by UK region

Region Typical cost
London £60,750
South East £56,250
South West £49,500
Midlands £45,000
North England £40,500
Scotland £42,750
Wales £40,500

How to save money

  • Order Velux windows direct from a builders merchant — saves 10–20 %
  • Use the existing landing for the staircase to avoid restructuring downstairs
  • Choose centre-pivot Velux for cleaning access from inside

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FAQs

How tall does the loft need to be for Velux?

You need at least 2.3 m at the ridge for a usable Velux conversion. Less than 2.2 m typically means a dormer.

Do I need planning permission for Velux loft?

No — Velux conversions are permitted development for nearly all UK houses, as long as the windows project less than 150 mm beyond the roof plane.

How long does a Velux loft take?

Typically 4–6 weeks on site, plus 6–8 weeks beforehand for design and building control.

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Disclaimer: Prices are guide ranges based on 2026 UK market data. Get quotes from local tradespeople for accurate pricing.