Guide prices in Dorchester
Timber upstand
Treated timber kerb built square and level to the maker's size
Insulated upstand
Kerb with insulation and the roof membrane turned up and dressed
Large or with trimming
Bigger kerbs or where joists need trimming first
Guide ranges for labour and materials, rooflight not included. 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.
Coverage in and around Dorchester
Distance is rarely the deciding factor. A roof in Weymouth, 7 miles from Dorchester, gets the same survey, the same written quote and the same fitting process as one in DT1, DT2 and DT3. What changes the price is the job itself: size of unit, roof type, access and lifting. Yeovil, around 18 miles out, is treated the same way.
What we do on the day
- Diagonals measured so the kerb is square before anything sits on it
- Treated timber frame fixed down to the deck and joists
- Kerb sized from the maker's drawing, internal and external dimensions both checked
- Size tolerance on the kerb — We build kerbs to a tight tolerance because rooflight glass is made to order and cannot be trimmed on site.
- Energy limit for site-built kerbs — We insulate upstands to meet the limit for site-built upstands, which is 0.35 W/m²K in England and Wales.
From arrival to clean-up
On the day, the fitters check the opening and the roof deck around it, then cut and fix treated timber to the maker's kerb size, square and level, with any fall the rooflight needs built in. Insulation goes on the faces that need it, and the roof membrane is turned up and dressed so the kerb is weathertight before anyone leaves. Most upstand jobs take half a day to a day.
Planning and building rules in England
England's rules in short: permitted development usually covers a rooflight on a house roof provided it doesn't stick out more than 0.15 m or rise above the ridge, though a listed building always needs consent and some streets have Article 4 directions. Building regulations apply to new openings, and replacements go through building control; as we are not registered with a competent person scheme, we use a building notice and show the fee on the quote. The energy limit for rooflights in existing homes is 2.2 W/m²K, and the 2026 Approved Document L, in force from 24 March 2027, keeps that figure.
Details that speed up your quote
What we cannot see, we have to guess, and guesses make quotes wider. So the more you send, the tighter the price. Useful: shots from the roof or garden, shots from the room underneath, a rough width and length, the roof finish, any access problems, and the product page if you have already ordered. Add the property postcode around DT1 and we will come back with a quote or a survey date.
Common questions in Dorchester
Do you make good inside after fitting?
Yes, where the quote includes it. Internal finishing usually means lining the reveal with plasterboard, taping or skimming, and fitting trim where it meets the ceiling. Some people prefer their own plasterer or decorator to finish off, which is fine. The written quote spells out exactly where our work stops, so nobody is left guessing about who does what once the unit is in.
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.
Does a rooflight need building regulations approval?
A new opening usually needs building regulations approval. A replacement is a controlled fitting: it must be self-certified by an installer registered with a competent person scheme or notified to building control. We are not registered with a scheme, so replacements we fit are notified to building control with a building notice, and the council's fee is shown on your quote.
Get in touch with the details of your Dorchester property and we will explain what the job involves and what it costs.
