Flat rooflights in Welling: what is involved?
For Welling homes and buildings we offer flat rooflights: fixed double or triple glazed rooflights for flat roofs and extensions. We measure first, specify to the opening and confirm any planning or building-control points before quoting.
Mansard and loft conversions are common across London, and roof windows are often set out alongside dormers on the rear slope. In Welling, as anywhere, flat rooflights are the usual choice for kitchen extensions, side returns and flat-roofed back rooms.
We work across Greater London, including Welling, and in neighbouring towns such as Bexleyheath and Bexley. Access, parking and how the glass reaches the roof are all checked at the survey.
Options we can specify in Welling
- Square, rectangular or long-format sizes
- Frame colours: anthracite, black, white or RAL
- Double or triple glazing
- Plastered or lined internal reveal
- Rain sensor if paired with an opening unit
- Even, top-down daylight across the whole room
- Slim sightlines from inside — mostly glass, little frame
Things we check at survey
- Rooflights count toward glazing in an extension, which matters for Building Regulations energy and overheating rules
- The roof membrane must be dressed up the upstand before the unit goes on
Planning, building control and Welling
Most rooflights on English houses do not need planning permission, provided they keep within 150 mm of the roof surface and below the ridge line. 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.
Building Regulations Approved Document L sets a limiting U-value of 2.2 W/m²K for new or replacement rooflights in existing homes, measured in the horizontal plane; roof windows need 1.4 W/m²K or a Band B energy rating. In an extension, glazing including rooflights is normally limited to 25% of the new floor area plus any windows or doors the extension covers, unless a whole-house calculation shows otherwise.
Read the planning permission guide before you commit to a design.
Guide prices for Welling
Guide prices for flat rooflights in Welling are the same as anywhere we work — what changes the price is the job: access, structure, scaffold and finishing.
| 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 |
What happens next
- Tell us what you have. Send the DA16 postcode, a rough size and a couple of photos.
- Measure and check. A surveyor visits Welling, measures and checks structure and access.
- Written price. You receive a fixed price listing the unit, the work and the lead time.
- Fitting and handover. We install, clean down and leave product and warranty documents.
Nearby towns
Other services in Welling
Questions about flat rooflights in Welling
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.
Will it make the room too hot?
A big unglazed-to-sky area can add solar gain in summer. Solar-control glass, a blind, or pairing a fixed unit with an opening one keeps it comfortable.
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 Welling?
Yes. On new extensions we fit once the opening and upstand are ready and coordinate dates with your builder.
How do I book a survey in Welling?
Send your postcode and, if you can, a photo of the roof and the room. We offer a survey date when we reply.
