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 Somerset?
In Somerset, a rooflight loft conversion typically costs £30,500–£46,000 for a typical rooflight conversion, including VAT at 20% (standard rate). Building costs in the South West are close to the UK average, so the figures for Somerset are close to our national guide. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rooflight conversion | £30,500–£46,000 |
| Higher specification | £46,000–£57,500 |
Your quote will depend mainly on:
- Bathroom or not
- Number of roof windows
- Floor and roof strengthening
- Storage and finishes
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 Somerset?
Here is how the rules work for a rooflight loft conversion 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
The work we manage on a rooflight loft conversion:
- Head-height survey
- Building control sign-off
- Staircase and fire-safe escape route
- Electrics, heating and plastering
- Floor joists and any steel beams
- Insulation between and under rafters
How long does it take?
Expect 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 Somerset
In parts of the South West, protected landscapes and conservation areas shape what can be built, so materials and roof forms are chosen carefully.
Towns we cover in Somerset include Mendip, Bath, Weston-super-Mare, Taunton, Yeovil and Bridgwater.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 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 Somerset
Is it cheaper than a dormer?
Yes, usually, because the roof shape stays the same. But you gain less full-height floor space.
Who approves a rooflight loft conversion in Somerset?
Planning matters in Somerset go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
Can I have a bathroom?
Yes, where there is enough head height at the shower or bath position.
How long does it take?
Usually 4 to 6 weeks on site.
How much does a rooflight loft conversion cost in Somerset?
In Somerset, a rooflight loft conversion typically costs £30,500–£46,000 for a typical rooflight conversion, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.