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 Mid Glamorgan?
In Mid Glamorgan, a rooflight loft conversion typically costs £27,500–£41,500 for a typical rooflight conversion, including VAT at 20% (standard rate). Prices across Wales are typically 8% below the UK average for this kind of work, which is reflected in the range for Mid Glamorgan. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rooflight conversion | £27,500–£41,500 |
| Higher specification | £41,500–£52,000 |
Your quote will depend mainly on:
- Number of roof windows
- Bathroom or not
- Fire safety upgrades
- 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 Mid Glamorgan?
Here is how the rules work for a rooflight loft conversion in Wales. In Wales roof windows that sit close to the roof slope are generally permitted development outside protected areas.
Building regulations in Wales are set by the Welsh Government. Approval comes from the council’s building control service or a registered building control approver, with inspections during the work and a completion certificate 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
Handled as part of most rooflight loft conversions:
- Staircase and fire-safe escape route
- Electrics, heating and plastering
- Head-height survey
- Floor joists and any steel beams
- Insulation between and under rafters
- Roof windows installed
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 Mid Glamorgan
Wales has many terraced valley streets, stone cottages and post-war estates, so extension designs are shaped by slopes, materials and local character.
Towns we cover in Mid Glamorgan include Bridgend, Merthyr Tydfil, Pontypridd, Aberdare, Caerphilly and Maesteg.
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
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about rooflight loft conversions in Mid Glamorgan
How much does a rooflight loft conversion cost in Mid Glamorgan?
In Mid Glamorgan, a rooflight loft conversion typically costs £27,500–£41,500 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.
Do I need planning permission for a rooflight loft conversion in Mid Glamorgan?
In Wales roof windows that sit close to the roof slope are generally permitted development outside protected areas.
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.
How long does it take?
Usually 4 to 6 weeks on site.
Do you build rooflight loft conversions in Mid Glamorgan?
Yes. We build rooflight loft conversions across Mid Glamorgan, including postcodes CF31, CF32, CF33, CF34 and CF35. Every project starts with a free home visit.
