What do flat rooflights in Windsor involve?
Our flat rooflights service in Windsor 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.
Orangery-style extensions with lanterns are popular across the South East, and solar-control glass makes a big difference on south-facing gardens. Typical uses for flat rooflights include kitchen extensions, side returns and flat-roofed back rooms.
Neighbouring towns include Slough (3 km) and Egham (7 km). We offer a survey date when we reply to your enquiry.
Options we can specify in Windsor
- Rain sensor if paired with an opening unit
- Integral or fitted blinds
- Solar-control or self-cleaning outer pane
- Square, rectangular or long-format sizes
- Insulated kerb or timber upstand built to suit
- Pairs with an opening unit where you also need ventilation
- Even, top-down daylight across the whole room
What to check first
- New openings in an existing roof need a structural check on joists
- Needs a properly formed upstand — usually at least 150 mm above the finished roof surface (check the manufacturer's figure)
Do you need permission in Windsor?
English householder permitted development (Class C) normally covers rooflights that stand no more than 0.15 m proud of the roof plane and stay below the highest part of the roof. A rooflight on a side-facing slope must be obscure-glazed, and fixed shut unless the opening part is more than 1.7 m above the floor.
Under Approved Document L, a rooflight added to an English home must achieve at least 2.2 W/m²K (horizontal plane), and a roof window 1.4 W/m²K or Window Energy Rating Band B. The Future Homes and Buildings Standards, published in March 2026, apply from 24 March 2027 and keep the 2.2 W/m²K limit for rooflights.
Read the planning permission guide before you commit to a design.
What do flat rooflights cost in Windsor?
These are typical supply-and-fit ranges. For an address in Windsor, 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 |
The process, step by step
- Tell us what you have. Send the SL4 postcode, a rough size and a couple of photos.
- Measure and check. A surveyor visits Windsor, measures and checks structure and access.
- Agree the quote. You approve the specification and price before anything is ordered.
- Fit and make good. We fit, seal, test and finish the reveal, then hand over the paperwork.
Nearby towns
Other services in Windsor
Flat rooflights in Windsor: 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.
Can a flat rooflight be walked on?
Not unless it is designed as a walk-on unit with structural laminated glass. A standard flat rooflight is for light only — if the roof is used as a terrace, choose a walk-on rooflight instead.
Do flat rooflights leak?
A well-fitted flat rooflight should not leak. Leaks almost always come from the upstand or membrane detailing, not the glass unit, which is why the upstand height and the way the roof covering is dressed up and under the frame matter more than the brand.
Can you work alongside my builder in Windsor?
Yes. On new extensions we fit once the opening and upstand are ready and coordinate dates with your builder.
Is the survey in Windsor free?
Yes for new installations. Repair visits are charged, and we tell you the price before we book.
