How Much Does a Loft Conversion Cost in the UK?
A loft conversion is often the most cost-effective way to add a bedroom to your home. Costs depend heavily on the type of conversion, the existing roof structure, and your location.
Typical Cost (UK, 2026)
Approximately £1,200–£2,500 per m² including labour and materials
All costs are indicative estimates. Obtain at least 3 quotes from qualified builders. Prices exclude VAT (20%).
Factors Affecting the Cost
Conversion type
A Velux conversion (roof lights only) is cheapest. A dormer conversion adds more space. A hip-to-gable or mansard conversion is most expensive.
Location
London prices are 25–35% above the national average.
Head height
Existing roof height determines how much space can be created. Low ridge heights may need structural changes.
Number of dormers
Each dormer adds cost. Rear dormers typically cost £10,000–£25,000 each.
En-suite bathroom
Adding an en-suite adds £5,000–£15,000 to the cost.
Cost Breakdown
| Item | Basic | Mid-range | High-end |
|---|---|---|---|
| Velux / roof lights conversion | £25,000 | £35,000 | £45,000 |
| Dormer conversion | £35,000 | £50,000 | £65,000 |
| Hip-to-gable conversion | £40,000 | £55,000 | £70,000 |
| Mansard conversion | £55,000 | £65,000 | £75,000+ |
Costs are indicative and exclude VAT. Regional variations apply.
Typical Timeline
6–12 weeks on site
Frequently Asked Questions
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