What do flat rooflights involve?
Across County Down, our flat rooflights work covers fixed double or triple glazed rooflights for flat roofs and extensions. Survey first, fixed price second, fitting third.
Northern Ireland has a mix of terraces, bungalows and rural farmhouses, and rooflights are a common upgrade when extending. Wind and rain off the Atlantic make upstand and flashing details important on Northern Irish roofs.
Towns in County Down
What you can choose
- Frame colours: anthracite, black, white or RAL
- Solar-control or self-cleaning outer pane
- Double or triple glazing
- Plastered or lined internal reveal
- Square, rectangular or long-format sizes
- Fixed units are simple, quiet and low-maintenance
- Double or triple glazed with a warm-edge spacer
Planning and building rules in Northern Ireland
Northern Ireland's householder permitted development allows rooflights within limits — no more than 15 cm projection on road-facing slopes and a 0.5 m margin from ridge, eaves and party walls. A side-facing window within 15 m of a neighbouring boundary must be obscure-glazed, and non-opening unless the opening part is more than 1.7 m above the floor.
Technical Booklet F1 (2022) asks for replacement windows and rooflights in existing homes to reach WER Band C or a U-value of 1.6 W/m²K, assessed in the vertical position. New dwellings must average 1.40 W/m²K across windows, roof windows and rooflights.
Flat rooflights prices in County Down
Prices below are shown including and excluding VAT. In County Down, 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.
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.
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.
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 County Down?
Yes — someone needs to let us into the room below and, where possible, show us how the roof is reached.
