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 Cumbria?
In Cumbria, a rooflight loft conversion typically costs £28,000–£42,500 for a typical rooflight conversion, including VAT at 20% (standard rate). That range is adjusted for the North West, where domestic building work typically costs around 6% below the national average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rooflight conversion | £28,000–£42,500 |
| Higher specification | £42,500–£53,000 |
Your quote will depend mainly on:
- Floor and roof strengthening
- Storage and finishes
- Number of roof windows
- Bathroom or not
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 Cumbria?
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
On a typical rooflight loft conversion we handle:
- Head-height survey
- Insulation between and under rafters
- Drawings and structural calculations
- Floor joists and any steel beams
- Electrics, heating and plastering
- Roof windows installed
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 Cumbria
Terraced streets across the North West often suit rear dormers and single-storey kitchen extensions.
Towns we cover in Cumbria include Carlisle, Barrow in Furness, Kendal, Whitehaven and Workington.
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
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 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 Cumbria
How long does it take?
Usually 4 to 6 weeks on site.
How much does a rooflight loft conversion cost in Cumbria?
In Cumbria, a rooflight loft conversion typically costs £28,000–£42,500 for a typical rooflight conversion, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
Who approves a rooflight loft conversion in Cumbria?
Planning matters in Cumbria 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.
What about fire safety?
The same escape rules apply as for any loft conversion, so a protected stairway and smoke alarms are typically needed.
