How we approach flat rooflights in Penarth
Our flat rooflights service in Penarth covers fixed double or triple glazed rooflights for flat roofs and extensions. Every job starts with a survey of the opening, the roof covering and the room below, and a fixed written price.
Wales sees a lot of wind-driven rain, particularly in the west, so upstand height and flashing laps matter more than anywhere. Typical uses for flat rooflights include kitchen extensions, side returns and flat-roofed back rooms.
We work across South Glamorgan, including Penarth, and in neighbouring towns such as Dinas Powys and Cardiff. Access, parking and how the glass reaches the roof are all checked at the survey.
What you can choose
- Solar-control or self-cleaning outer pane
- Insulated kerb or timber upstand built to suit
- Frame colours: anthracite, black, white or RAL
- Double or triple glazing
- Integral or fitted blinds
- Even, top-down daylight across the whole room
- Fixed units are simple, quiet and low-maintenance
What to check first
- New openings in an existing roof need a structural check on joists
- Rooflights count toward glazing in an extension, which matters for Building Regulations energy and overheating rules
Planning, building control and Penarth
Welsh householder permitted development (Class C) allows rooflights that project no more than 15 cm and sit no higher than the existing roof — but not in conservation areas, National Parks, AONBs or World Heritage Sites. A side-facing rooflight within 10.5 m of the boundary must be obscure-glazed, and non-opening unless the opening part is more than 1.7 m above the floor.
In Wales the limiting values are 2.2 W/m²K for a rooflight and 1.4 W/m²K (or WER Band B) for a roof window in an existing house. A revised Welsh Approved Document L takes effect on 4 March 2027; rooflights in new dwellings stay at 2.2 W/m²K.
See our building regulations guide for U-values, glazing limits and self-certification.
Guide prices for Penarth
These are typical supply-and-fit ranges. For an address in Penarth, scaffold, a hoist for heavy glass, or a new structural opening can move the figure, which is why we survey first.
| Option | Guide price inc VAT | Ex VAT |
|---|---|---|
| Large or triple glazed (1500 × 2500 mm and up) | £2,395 – £4,195 | £1,995 – £3,495 |
| Mid-size double glazed (1000 × 2000 mm) Typical | £1,675 – £2,395 | £1,395 – £1,995 |
| Small double glazed (up to 1000 × 1000 mm) | £1,195 – £1,795 | £995 – £1,495 |
How the job runs
- Send the details. Postcode, rough size and a photo of the roof and room.
- Survey. We measure the opening, check the roof build-up and agree the options.
- Fixed quote. Product, work and price in writing — nothing is ordered until you agree.
- Fit and make good. We fit, seal, test and finish the reveal, then hand over the paperwork.
Neighbouring towns
Related work in Penarth
Flat rooflights in Penarth: questions
Can you fit into my existing flat roof?
Yes. We form a new opening, trim the joists, build and waterproof an upstand and make good the ceiling. A survey confirms the joist direction and roof build-up first.
Double or triple glazing?
Double glazing suits most domestic jobs. Triple glazing improves thermal performance and cuts noise from rain, which is worth it over bedrooms or where the energy calculation is tight.
How long does it take?
Fitting into a prepared upstand usually takes a day. Forming a new opening in an existing roof, including making good inside, is often two to three days.
Can you work alongside my builder in Penarth?
Yes. On new extensions we fit once the opening and upstand are ready and coordinate dates with your builder.
Will I need planning permission in Penarth?
In Wales a rooflight on a house is usually permitted development if it stands no more than 15 cm proud of the roof, except on protected land such as conservation areas and National Parks, where permission is needed.
