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 Hampstead?
In Hampstead, a rooflight loft conversion typically costs £39,000–£58,500 for a typical rooflight conversion, including VAT at 20% (standard rate). The guide for Hampstead reflects typical costs in London, roughly 30% above the UK-wide figure. 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 biggest cost drivers are:
- Staircase position
- Storage and finishes
- Number of roof windows
- Floor and roof strengthening
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 Hampstead?
The approval route for Hampstead 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.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
What we take care of:
- Insulation between and under rafters
- Head-height survey
- Staircase and fire-safe escape route
- Roof windows installed
- Floor joists and any steel beams
- Drawings and structural calculations
How long does it take?
Expect 4 to 6 weeks on site. Before that, surveys, drawings and approvals usually take 6 to 12 weeks, longer if the council asks for changes.
Building in Hampstead
Space is at a premium in London, so homeowners often build out into the side return or up into the roof rather than move.
If your home is in Hampstead or close by in Highgate, Golders Green and Camden, a free home visit is the first step.
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 fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed 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 Hampstead
How long does it take?
Usually 4 to 6 weeks on site.
Is it cheaper than a dormer?
Yes, usually, because the roof shape stays the same. But you gain less full-height floor space.
How much does a rooflight loft conversion cost in Hampstead?
In Hampstead, 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.
Who approves a rooflight loft conversion in Hampstead?
Planning matters in Hampstead go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
