What is a rooflight loft conversion?
A rooflight loft conversion (sometimes called a roof window conversion) keeps the existing roof shape and adds roof windows that sit flush with the slope. The floor is strengthened, a staircase is added and the space is insulated and finished.
How much does a rooflight loft conversion cost in Horley?
In Horley, a rooflight loft conversion typically costs £33,500–£50,500 for a typical rooflight conversion, including VAT at 20% (standard rate). Building costs in the South East run about 12% above the UK average, and the figures for Horley are adjusted to reflect that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rooflight conversion | £33,500–£50,500 |
| Higher specification | £50,500–£63,000 |
What moves the price most:
- Staircase position
- Bathroom or not
- Storage and finishes
- Number of roof windows
For a figure based on your own measurements, try the guide price tool, then book a free home visit for a fixed quote.
Do you need planning permission for a rooflight loft conversion in Horley?
Before anything is built in Horley, we confirm which approvals apply in England. In England roof windows are permitted development if they project no more than 15 centimetres from the roof slope and side-facing windows are obscure-glazed. Listed buildings need consent.
Where work involves a shared wall, building on the boundary, or digging foundations within 3 metres of a neighbour’s building and deeper than its foundations (or within 6 metres for deeper work), the Party Wall etc. Act 1996 applies and notices must be served before work starts.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
On a typical rooflight loft conversion we handle:
- Drawings and structural calculations
- Electrics, heating and plastering
- Building control sign-off
- Head-height survey
- Insulation between and under rafters
- Floor joists and any steel beams
How long does it take?
Allow 4 to 6 weeks on site. Design and approvals come first and typically take 6 to 12 weeks, depending on the approval route.
Building in Horley
The South East has a broad mix of housing, from Victorian terraces in the towns to post-war semis and newer estates, so extension types vary street by street.
We work across Horley and neighbouring areas such as Crawley, Redhill and Reigate. Postcodes we cover in Horley include RH6.
How it works
- 01
Free visit
We look at the property, talk through what you want and measure up. There is no charge and no obligation.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about rooflight loft conversions in Horley
Who approves a rooflight loft conversion in Horley?
Planning matters in Horley go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
Is it cheaper than a dormer?
Yes, usually, because the roof shape stays the same. But you gain less full-height floor space.
How much head height do I need?
Around 2.2 metres or more from the top of the ceiling joists to the ridge is a good starting point. Insulation and new floor joists reduce the height.
What about fire safety?
The same escape rules apply as for any loft conversion, so a protected stairway and smoke alarms are typically needed.
How much does a rooflight loft conversion cost in Horley?
In Horley, a rooflight loft conversion typically costs £33,500–£50,500 for a typical rooflight conversion, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.