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RooflightInstallers.co.uk
Castlereagh · BT6 · County Antrim

New rooflight in an existing roof in Castlereagh

Cut the opening. Trim the joists or rafters. Build the upstand or fit the flashing kit. Fix the unit, seal it, finish the inside. On a new opening, that is the whole job in plain terms, and each step has to be right for the next one to work. We carry out this work in Castlereagh and across County Antrim, either installing a unit you have bought or sourcing one for you. You get a written quote with the scope set out, and a written workmanship guarantee on the fitting with its terms on that quote.

Guide price from £2,295 · Supply & fit, including structure and making good; building control or warrant fees extra

What the job costs in Castlereagh

Small fixed unit

£2,295 – £3,345including VAT at 20%

Opening cut, joists trimmed, upstand built, roof covering made good, plasterboard reveals ready for decoration

Medium fixed unit

£3,345 – £4,795including VAT at 20%

As the small unit, with a larger opening up to about 1 × 2 m and additional trimming

Large or opening unit

£4,795 – £7,795including VAT at 20%

Bigger structural work or an electric opening unit

Guide ranges for supply & fit, including structure and making good; building control or warrant fees extra. Your price is fixed in a written quote after we have seen photos or surveyed. Scaffold, access towers or a crane are priced separately if the job needs them, and building control fees, where a job needs them, are shown as their own line.

Areas around Castlereagh we cover

Looking at a property near Castlereagh but not quite in it? We work across BT6, BT5 and BT7 and outwards to Belfast, Newtownabbey and Lisburn. Give us the full postcode when you get in touch, because access, parking and the route for a large unit all depend on the exact street. Those details shape the quote for any job around Castlereagh.

Already bought your unit?

Supply and fit tends to suit people who would rather not pick a unit from a catalogue. We look at the roof, the opening and how you use the room, then put a new rooflight on the quote that fits all three. Fit-only suits people who already know what they want, or have one on site. We are happy with either. The difference is who stands behind what: on fit-only, the maker or retailer covers the product, and our workmanship guarantee covers the installation.

On the day, we cover

  • Roof membrane, felt or tiles made good and dressed up the upstand
  • Rooflight fitted, sealed and checked for even clearance on every side
  • Insulated upstand built square, level and to the maker's height
  • Upstand energy performance — We build the upstand to meet the energy limit for site-built upstands, not just to hold the rooflight up.
  • Planning for your roof — We check whether the new rooflight falls within permitted development for your house and nation.

What happens on the day

Arrive and agree the plan. Sheet the floor and furniture. Set up the ladder, tower or scaffold. Check the opening, the upstand or flashing, and the unit against the paperwork. Fix and pack a new rooflight level. Seal it into the roof. Line the reveal or fit the ceiling trim. Clean the glass, clear the waste, and talk you through it. That is the shape of most fitting days, and for this type of job it usually takes two to three days.

Do you need permission in Castlereagh?

In Northern Ireland, the energy standard for a new or replacement rooflight or roof window in an existing home is WER Band C or a U-value of 1.6 W/m²K, under Technical Booklet F1. Cutting a new opening alters the roof structure, so a building control application is expected; confirm with the council's building control team. Planning permitted development covers many rooflights on houses if they stay below the ridge, project no more than 15 cm on a road-facing slope and sit at least 0.5 m from the ridge, eaves and verges.

Before you get in touch

A fast quote needs five things: a photo of the roof from outside, one from the room below, rough sizes of the opening or the space, the roof covering (felt, single-ply, fibreglass, tiles, slate or metal), and a note on access. If you have already bought the unit, add the product link or spec sheet. And give us the postcode, BT6 or a neighbouring district.

Common questions in Castlereagh

Does a rooflight need building control approval?

In Northern Ireland a new opening alters the roof structure, so expect a building control application; confirm the position with your council, including for replacements. The new rooflight must meet WER Band C or 1.6 W/m²K. We confirm what applies before you commit.

Do you cover Castlereagh?

Yes. Fitters travel to addresses in Castlereagh and the surrounding districts, including BT6. We do not run an office there; the survey and the fitting happen at your property. A few island and remote postcodes are covered by arrangement; if yours is one, we confirm travel and dates before quoting.

Do you offer trade rates for builders and roofers?

We carry out subcontract fitting for builders, roofers, extension companies and commercial contractors. Pricing is per job or per schedule of units, agreed in writing before we start. We can work to your programme, fit on your upstand or build our own, and leave the opening ready for the next trade. Send drawings or a unit schedule and we will come back with a trade quote.

For a free, no-obligation quote in Castlereagh, use the form or call us with the details of your roof.

Rear extension at dusk with lit rooflights and a roof lantern
Ready when you are

New openings in Castlereagh

Send photos and rough sizes, or ask for a survey for install work. One fixed written price before anything starts.

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