Castlereagh · County Down
Roof Lanterns in Castlereagh
Homeowners in Castlereagh can get a written roof lantern quote that fixes the price for the size, shape, glass, colour and vents shown.
- BT6
- BT5
- BT7
- Guide from £1,095
About opening skylights in Castlereagh
Opening skylights and lantern vents can be manual or electrically operated, often with a rain sensor that closes them automatically when it starts to rain. Electric vents need a power supply planned before plastering, so the wiring route is agreed at survey when an opening option is chosen.
Cutting a new opening for a roof lantern or skylight usually means trimming joists or rafters, so the roof can carry the load around the hole. Building regulations approval is generally needed for a new rooflight, covering structure, energy performance and, near a boundary, fire performance.
The price of a roof lantern or skylight depends on the size and shape, glass specification, frame colour, opening vents or electric operation, and whether the upstand already exists or needs building. Access to the roof and lifting large units add labour. See the guide prices for typical ranges.
Warm, moist air rises and collects in a roof lantern, so condensation can form on cold winter mornings, especially over kitchens and bathrooms. Thermally broken frames, warm-edge spacers and good room ventilation reduce it, and opening vents in the lantern can release warm air in summer.
What you get
- Removal and disposal of an old lantern or skylight
- Survey of the roof, opening, upstand and drainage
- Sealed double glazed units with laminated inner pane options
- Made-to-measure aluminium roof lantern or framed skylight

Working in Castlereagh
- Postcodes covered
- BT6, BT5, BT7 and the surrounding area, including Belfast, Dundonald and Carryduff
- Coast
- Castlereagh is about 5 km from the coast or a tidal estuary, so salt air and wind-driven rain are worth planning for. Coastal lanterns face salt deposits on the glass and frames and strong uplift from wind on exposed roofs. Marine-grade coatings, stainless fixings and secure fixing to a well-built upstand matter, and salt film may need rinsing more often than self-cleaning glass manages alone.
- Daylight and sun
- In Castlereagh the midwinter sun reaches about 12° above the horizon at noon, with roughly 7.0 hours of daylight, rising to about 59° and 17.0 hours in midsummer. Overhead glazing receives far more light than a wall window of the same size, especially when the sun is high in summer. South-facing lanterns may need solar-control glass, while low winter sun and north-facing rooms benefit from clear, high light-transmission low-E glass.
- Access and setting
- Rural roofs collect more leaves, moss and bird debris, so lanterns need clear upstand drainage and regular checks. Exposed sites see higher wind loads and driving rain, and older outbuildings may need the roof structure strengthening before a lantern is added.
- Rules in Northern Ireland
- Technical Booklet V covers safety glazing in Northern Ireland, including glass in and around doors and low-level glazing where people could walk into it.
Guide prices in Castlereagh
| Typical job | Guide price inc VAT |
|---|---|
| Lantern 1500 × 1000 mm, fitted to a kerb | £1,395 – £1,795 |
| Lantern 2000 × 1000 mm | £1,695 – £2,095 |
| Lantern 3000 × 1500 mm | £2,795 – £3,695 |
| Flat glass rooflight 1000 × 1000 mm | £1,095 – £1,395 |
Get a guide price for your size
Replacement windows on houses in Northern Ireland are often permitted development, but conservation areas and listed buildings can need consent. Check with the council's planning office.
Options to choose between
Solar-control glass
Neutral or blue-tinted coatings that reduce heat build-up under south or west-facing lanterns while keeping daylight levels high.
Rectangular hipped lantern
A long ridge with hipped ends, suiting most rectangular extensions and kitchens, sized to the opening and the room below.
Frame colours
Powder-coated aluminium in grey, black, white or other RAL colours, often dual colour to suit the roof and the room.
Roof Lanterns in Castlereagh: questions
Can I replace my old polycarbonate roof lantern with glass?
Yes, in most cases. A glass lantern is heavier than polycarbonate, so the upstand and roof structure must be able to carry it. If the upstand is sound, level and the right size, a new aluminium lantern can usually sit on it. If not, the upstand is rebuilt first, which the survey will identify.
Does fitting a roof lantern need building regulations approval?
A new roof lantern or skylight generally needs building regulations approval, because the roof structure is cut and must be supported, and the unit must meet energy standards. Fire performance also matters near a boundary. Replacing a lantern on an existing sound upstand is simpler, and we explain which route applies at survey.
How much does a roof lantern cost?
The cost of a roof lantern depends on its size and shape, the glass specification, frame colour, any opening vents, and whether the upstand exists or needs building. Access to the roof and lifting a large lantern also affect labour. See the guide prices for typical ranges; the written quote fixes the price for your exact specification.
How long does it take to fit a roof lantern?
Fitting a roof lantern on a prepared upstand usually takes a day or less for a typical size, longer for large or complex shapes. The lantern is made to order first, and the lead time depends on its size, shape and colour. Building or rebuilding an upstand is separate roofing work that comes before fitting.
Do you cover Castlereagh for roof lanterns?
Yes. We can quote for roof lanterns across Castlereagh and the surrounding County Down area, including postcode districts BT6, BT5 and BT7, and nearby Belfast, Dundonald and Carryduff. Start with your postcode on the quote form and a glazier will arrange a free survey before giving you a written quote.
Get a written quote in Castlereagh
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.