What do flat rooflights involve?
Across Lancashire, our flat rooflights work covers fixed double or triple glazed rooflights for flat roofs and extensions. Survey first, fixed price second, fitting third.
Rear kitchen extensions on North West semis often have small domes from decades ago that leak or have yellowed. Converted mills and warehouses in the North West often have large rooflights or glass roofs that need specialist replacement.
Towns in Lancashire
What you can choose
- Integral or fitted blinds
- Plastered or lined internal reveal
- Frame colours: anthracite, black, white or RAL
- Square, rectangular or long-format sizes
- Rain sensor if paired with an opening unit
- Slim sightlines from inside — mostly glass, little frame
- Fixed units are simple, quiet and low-maintenance
Planning and building rules in England
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.
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. Replacing a rooflight or roof window can be self-certified by an installer registered with an authorised competent person scheme; otherwise building control approval is needed.
Flat rooflights prices in Lancashire
Prices below are shown including and excluding VAT. In Lancashire, as elsewhere, making good inside and access equipment are the main variables.
| 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
- Tell us about the roof. Send the postcode, rough sizes and a photo or two through the form, WhatsApp or the guide-price tool.
- Free survey. For new installations a surveyor measures the opening, checks the roof build-up and talks through glass and options.
- Fixed written quote. You get the product, the work and the price in writing. Nothing is ordered or paid for until you agree.
- Fitting and handover. We fit, seal and make good, then hand over product data, warranties and any certificate paperwork.
Flat rooflights in nearby areas
Common questions
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.
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.
Do I need to be at home for the survey in Lancashire?
Yes — someone needs to let us into the room below and, where possible, show us how the roof is reached.
