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 Kempston?
In Kempston, a rooflight loft conversion typically costs £32,000–£47,500 for a typical rooflight conversion, including VAT at 20% (standard rate). We start from a UK-wide guide and adjust it for the East of England, where labour and materials are typically about 6% above average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rooflight conversion | £32,000–£47,500 |
| Higher specification | £47,500–£59,500 |
What moves the price most:
- Fire safety upgrades
- Staircase position
- 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 Kempston?
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.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
What we take care of:
- Electrics, heating and plastering
- Building control sign-off
- Head-height survey
- Staircase and fire-safe escape route
- Roof windows installed
- Floor joists and any steel beams
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 Kempston
Many towns in the East of England have estates built since the 1970s, where garage conversions and rear extensions are popular.
From MK42 outwards, we take on projects throughout Kempston and the surrounding parts of Bedfordshire.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about rooflight loft conversions in Kempston
How long does a rooflight loft conversion take in Kempston?
Typically 4 to 6 weeks on site. Design and approvals beforehand usually take 6 to 12 weeks.
Can I have a bathroom?
Yes, where there is enough head height at the shower or bath position.
How much does a rooflight loft conversion cost in Kempston?
In Kempston, a rooflight loft conversion typically costs £32,000–£47,500 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.
