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 Farnborough?
In Farnborough, a rooflight loft conversion typically costs £33,500–£50,500 for a typical rooflight conversion, including VAT at 20% (standard rate). That range is adjusted for the South East, where domestic building work typically costs around 12% above the national average. 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 |
Your quote will depend mainly on:
- Fire safety upgrades
- Bathroom or not
- Floor and roof strengthening
- Number of roof windows
Your exact price depends on the survey and drawings. The guide price tool gives a quick range in the meantime.
Do you need planning permission for a rooflight loft conversion in Farnborough?
Before anything is built in Farnborough, 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.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
Handled as part of most rooflight loft conversions:
- Drawings and structural calculations
- Roof windows installed
- Floor joists and any steel beams
- Building control sign-off
- Insulation between and under rafters
- Staircase and fire-safe escape route
How long does it take?
The build itself usually takes 4 to 6 weeks on site. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in Farnborough
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.
Farnborough sits in Hampshire, about 14 miles south-east of Reading. We cover the whole of Farnborough, including postcodes GU11.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about rooflight loft conversions in Farnborough
Who approves a rooflight loft conversion in Farnborough?
Planning matters in Farnborough go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
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.
How much does a rooflight loft conversion cost in Farnborough?
In Farnborough, 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.
Is it cheaper than a dormer?
Yes, usually, because the roof shape stays the same. But you gain less full-height floor space.
What about fire safety?
The same escape rules apply as for any loft conversion, so a protected stairway and smoke alarms are typically needed.
