RENOVATION · UPDATED 2026-04-01
Loft Conversion Cost London 2026 · Full Price Breakdown
£40,000 – £80,000 full project
A loft conversion in London typically costs £40,000–£80,000, adding significant value to your home. LPG manages all aspects · structural, electrical, plumbing, and finishing.
Loft Conversion price breakdown — London 2026
| Job | Price range | Unit |
|---|---|---|
| Velux loft conversion (no extension) | £25,000 – £45,000 | full job |
| Dormer loft conversion | £40,000 – £65,000 | full job |
| Hip-to-gable conversion | £50,000 – £80,000 | full job |
| Mansard loft conversion | £55,000 – £90,000 | full job |
What affects the price
- Conversion type. Velux (roof lights only) is cheapest; dormers and hip-to-gable conversions cost more.
- Intended use. Adding a bedroom with en-suite requires more plumbing and electrical work.
- Structural complexity. Complex roof structures need more engineering work.
Frequently asked questions
Do I need planning permission for a loft conversion?
Many loft conversions fall under Permitted Development rights. Mansard conversions and those in conservation areas typically require full planning permission.
How much value does a loft conversion add to a London property?
A loft conversion typically adds 15–25% to property value in London · often more than the conversion cost.
Related cost guides
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