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 Mitcham?
In Mitcham, a rooflight loft conversion typically costs £39,000–£58,500 for a typical rooflight conversion, including VAT at 20% (standard rate). Prices across London are typically 30% above the UK average for this kind of work, which is reflected in the range for Mitcham. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rooflight conversion | £39,000–£58,500 |
| Higher specification | £58,500–£73,000 |
The main things that change the cost:
- Number of roof windows
- Fire safety upgrades
- Floor and roof strengthening
- Storage and finishes
A guide range is only a starting point: the guide price tool gives an instant figure for your size, and a free survey turns it into a fixed quote.
Do you need planning permission for a rooflight loft conversion in Mitcham?
The approval route for Mitcham is set by planning law 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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
On a typical rooflight loft conversion we handle:
- Staircase and fire-safe escape route
- Roof windows installed
- Insulation between and under rafters
- Floor joists and any steel beams
- Drawings and structural calculations
- Building control sign-off
How long does it take?
Allow 4 to 6 weeks on site. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in Mitcham
Space is at a premium in London, so homeowners often build out into the side return or up into the roof rather than move.
Mitcham sits in Greater London, about 7 miles south of central London. We cover the whole of Mitcham, including postcodes CR4.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about rooflight loft conversions in Mitcham
How long does a rooflight loft conversion take in Mitcham?
Typically 4 to 6 weeks on site. Design and approvals beforehand usually take 6 to 12 weeks.
How much does a rooflight loft conversion cost in Mitcham?
In Mitcham, a rooflight loft conversion typically costs £39,000–£58,500 for a typical rooflight conversion, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
Can I have a bathroom?
Yes, where there is enough head height at the shower or bath position.
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.