Flat rooflights for Belfast: the essentials
For Belfast 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.
Conservation areas and listed buildings in Northern Ireland are excluded from householder permitted development, so we check before quoting. In Belfast, as anywhere, flat rooflights are the usual choice for landings, bathrooms and rear extensions with flat roofs.
We cover all of Belfast and the BT1 district, and nearby Castlereagh and Newtownabbey.
Specification options
- Square, rectangular or long-format sizes
- Frame colours: anthracite, black, white or RAL
- Plastered or lined internal reveal
- Integral or fitted blinds
- Rain sensor if paired with an opening unit
- Inner pane laminated for safety overhead
- Slim sightlines from inside — mostly glass, little frame
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 Belfast
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. 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.
Northern Ireland's energy rules assess rooflight U-values in the vertical position — unlike England and Wales — and expect 1.6 W/m²K or Band C for replacements. Extensions follow a 25% glazing allowance in Technical Booklet F1.
Our planning guide covers each nation in more detail.
What do flat rooflights cost in Belfast?
Prices below are shown including and excluding VAT. In Belfast, 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 |
What happens next
- Get in touch. Use the form, WhatsApp or the guide-price tool with your Belfast address.
- Free site visit. For new installs we survey free, measure and confirm the roof detail.
- Written price. You receive a fixed price listing the unit, the work and the lead time.
- Installation day. Usually one day into a prepared opening, longer for new openings.
Flat rooflights near Belfast
Other services in Belfast
Flat rooflights in Belfast: questions
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.
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.
How do I book a survey in Belfast?
Send your postcode and, if you can, a photo of the roof and the room. We offer a survey date when we reply.
Will I need planning permission in Belfast?
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.
