What do flat rooflights in Derry/Londonderry involve?
Thinking about flat rooflights in Derry/Londonderry? The short answer: fixed double or triple glazed rooflights for flat roofs and extensions. The longer answer depends on your roof, which is why we survey before we price.
Wind and rain off the Atlantic make upstand and flashing details important on Northern Irish roofs. In Derry/Londonderry, as anywhere, flat rooflights are the usual choice for kitchen extensions, side returns and flat-roofed back rooms.
We cover all of Derry/Londonderry and the BT48 district, and nearby Strabane and Limavady.
Choices for your Derry/Londonderry project
- Plastered or lined internal reveal
- Solar-control or self-cleaning outer pane
- Rain sensor if paired with an opening unit
- Insulated kerb or timber upstand built to suit
- Frame colours: anthracite, black, white or RAL
- Pairs with an opening unit where you also need ventilation
- Even, top-down daylight across the whole room
Before you order: points to check
- Rooflights count toward glazing in an extension, which matters for Building Regulations energy and overheating rules
- Needs a properly formed upstand — usually at least 150 mm above the finished roof surface (check the manufacturer's figure)
Planning and building rules for Derry/Londonderry
In Northern Ireland, roof alterations come under Class B of the 2015 order: a rooflight facing a road must not project more than 15 cm and must sit at least 0.5 m from the ridge, eaves, verge and party wall. Listed buildings also need listed building consent from the council.
For homes in Northern Ireland, Technical Booklet F1 sets 1.6 W/m²K (or WER Band C) for replacement glazing including rooflights. New dwellings must average 1.40 W/m²K across windows, roof windows and rooflights.
See our building regulations guide for U-values, glazing limits and self-certification.
What do flat rooflights cost in Derry/Londonderry?
The ranges below are typical for straightforward jobs; your fixed price follows a survey of your roof.
| 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
- Get in touch. Use the form, WhatsApp or the guide-price tool with your Derry/Londonderry address.
- Survey. We measure the opening, check the roof build-up and agree the options.
- 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
Related work in Derry/Londonderry
Common questions
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.
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.
Do you fit flat rooflights in Derry/Londonderry?
Yes. We survey and fit flat rooflights in Derry/Londonderry and across County Londonderry. Send your postcode and we will offer a survey date when we reply.
Will I need planning permission in Derry/Londonderry?
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.
