Guide prices
About 1 × 2 m
Aluminium lantern, double glazed, fitted and glazed on a ready upstand
About 1.5 × 3 m
Mid-size lantern, solar-control glass options
2 × 4 m and over
Large lanterns, lifting gear on the day
Guide ranges for supply & fit. 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.
Covering DT1 and neighbouring districts
If you also own a property or a business unit in Weymouth, Yeovil or Poole, that is no problem. We can survey and quote both, and where it suits, line the fitting days up together. Every address is reached by fitters travelling to it from their current jobs, and DT1, DT2 and DT3 sit comfortably within that pattern.
What we check on a supplied unit
A damaged delivery is a frequent snag on fit-only work. Before the day, unpack a roof lantern, photograph it, and tell the seller about any cracks or scuffs, because claims are much easier made early. We will also ask for the model or a link, so we can read the maker's instructions and check the builder's opening size and the upstand height it expects. If everything lines up, we fit it. If not, we explain what needs changing first.
Included in the work
- Caps, end closures and ridge trims fitted and sealed
- Roof membrane checked where it meets the lantern frame
- Frame assembled on the kerb in the maker's set order
- Level, not to a fall — We set or check the kerb level unless your lantern's maker says otherwise.
- Following the build order — We assemble lanterns in exactly the sequence the instructions give.
A typical installation day
On the day, you need to be in at the start and at the end. In between, the fitters get on with it. They will want the room below cleared where possible, a parking spot if you have one, and somewhere to set the unit down safely. After checking the opening and the upstand or flashing, they fix a roof lantern, seal it and finish the inside. Packaging and any old unit leave with them unless the quote says otherwise.
Planning, building control and Dorchester
In England, a new rooflight opening generally needs building regulations approval because the roof structure is altered and the glazing must meet energy rules: 2.2 W/m²K for a rooflight in an existing home, or 1.4 W/m²K (or WER Band B) for a roof window. Planning is often not needed on a house: permitted development covers rooflights that stand no more than 0.15 m proud of the roof slope and sit below the highest part of the roof. Flats, listed buildings and areas with an Article 4 direction are different, so we check your address first.
Help us quote accurately
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, DT1 or nearby, confirms travel.
Common questions in Dorchester
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.
Can you remove and dispose of the old rooflight?
Yes. Taking out the old unit is part of any replacement job, and it leaves with the rest of the waste unless you ask to keep it. Old domes, glass and frames go through proper waste routes. If removal turns up a rotten kerb or damaged decking, we show you what we have found and agree the repair with you before going any further.
Can you fit the roof lantern I bought online?
Yes, fit-only is one of our core services. Send the product link or spec, photos of the roof and rough sizes, and we can usually price it from those. Before fitting we check the delivery for damage, which should be reported to the seller, plus the size against the builder's opening and the upstand height. The product warranty stays with the maker or seller, and our guarantee covers the fitting.
Planning a roof lantern in Dorchester? Tell us about the roof and we will come back with a clear price in writing.

