What the job costs in Derry/Londonderry
Like-for-like swap
Old dome or unit removed and disposed of, new glass rooflight fitted to the existing sound kerb
New upstand and swap
Old kerb taken off, new insulated upstand built, roof covering made good, new unit fitted
Opening or large unit
Electric or larger replacement, including making good inside
Guide ranges for supply & fit; building control notice fee extra in England and Wales. 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 Derry/Londonderry we cover
Our fitters come to you. For Derry/Londonderry that covers BT48, BT47 and BT49, plus nearby Coleraine and Omagh. We do not keep a yard or showroom in the area, and you do not need to visit one. The survey happens at your property or, for fit-only work, from the photos you send. Dates follow fitter availability, which we confirm when you accept the quote.
What we check on a supplied 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 replacement 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.
Included in the work
- Kerb inspected for rot, height, level and fall once the old unit is off
- Roof membrane repaired and turned up where it meets the kerb
- Building notice given to the council in England and Wales, with its fee on the quote
- Is the kerb worth keeping? — We decide whether the existing kerb can stay only after checking it for rot, height and squareness.
- Leaks that are not the rooflight — We look at the roof around the unit before blaming the rooflight.
Fitting your replacement rooflight, step by step
Protection comes before tools. Floors, furniture and stairs get covered, and the ceiling below the opening is sheeted to catch dust. Up top, the fitters confirm the opening is square and the upstand or flashing suits what the maker specifies. Fixing follows, then weather-sealing into the membrane, felt or tiles. Only once the roof is tight do they turn to the internal reveal. Time on site for a replacement rooflight: one day, weather permitting.
Planning and building rules in Northern Ireland
For a home in Northern Ireland, check planning first: rooflights are excluded from permitted development in conservation areas and within the curtilage of listed buildings, and elsewhere must keep 0.5 m clear of the ridge, eaves and verges. Then building control: a new opening alters the roof structure, so expect a building control application and confirm with your council, and the glazing must achieve WER Band C or 1.6 W/m²K. We check both for your address before quoting.
Details that speed up your quote
Each detail you send takes a question off our list. Photos inside and out show the opening and the ceiling. Rough measurements tell us the unit size. The roof covering tells us how it will be sealed in. Access notes tell us whether a tower or scaffold is needed. A product link, if you have one, lets us check it against the opening. Your postcode, BT48 or nearby, confirms travel.
Common questions in Derry/Londonderry
Can you fit a rooflight in winter or when it is raining?
Yes, within limits. Cold is less of a problem than wet, because membranes, primers and sealants need a dry surface to bond. We plan fitting days around the forecast and may move a date if heavy rain is due. If the roof has to be opened up, it is not left overnight without a temporary weather seal, so the room below stays dry while the work is finished.
What if my roof opening is the wrong size for the replacement rooflight?
We find out before the fitting day, not on it. If the opening is slightly out, it can usually be adjusted by trimming or by packing out the upstand. If it is a long way off, the choice is between altering the opening and changing the unit. Bear in mind that rooflights are often sold by builder's opening size rather than external size, so check which one your measurement refers to.
Do you need scaffolding to fit a rooflight?
Not always. Single-storey roofs can often be reached safely with ladders, a tower or edge protection. Higher roofs, steep pitches and large units usually need scaffold or a mobile platform, and heavy glass may need a crane. We assess access from your photos or at the survey, and any scaffold or lifting cost is shown as its own line on the written quote.
Planning a replacement rooflight in Derry/Londonderry? Tell us about the roof and we will come back with a clear price in writing.

