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RooflightInstallers.co.uk
Portishead · BS20 · Somerset

Loft conversion roof windows in Portishead

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 Portishead and across Somerset, 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 £1,795 · Supply & fit

Guide prices

Pair of windows

£1,795 – £2,745including VAT at 20%

Two roof windows into a loft room, flashings and linings

Three or four windows

£2,745 – £4,545including VAT at 20%

Bigger loft rooms or stairwells

Balcony or combination

£4,545 – £7,195including VAT at 20%

Balcony-style or stacked window combinations

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.

Areas around Portishead we cover

Covering Portishead means covering the people who live and work there, not a single postcode. We take on domestic and commercial jobs in BS20, BS48 and BS21, and are happy to quote further out in Nailsea and Clevedon. If your address sits between towns, tell us and we will confirm whether it falls in our normal area or needs travel set out separately on the quote.

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 loft roof window 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

  • Matching or combination flashing kits for windows side by side
  • Rafters trimmed and doubled where the openings need them
  • Insulation collars fitted so the room's insulation meets each frame
  • Energy performance in a loft — We check every window meets the energy limit for roof windows in existing homes.
  • Balcony-style windows — We check the rafters and the roof pitch before recommending balcony-style windows.

What happens on the 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 loft roof window, seal it and finish the inside. Packaging and any old unit leave with them unless the quote says otherwise.

Regulations for Portishead properties

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

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 BS20 and we will come back with a quote or a survey date.

Common questions in Portishead

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.

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.

Will my new loft roof window leak?

A correctly fitted unit should not. Leaks usually trace back to the detail around the frame: an upstand that is too low, a membrane or flashing that is not dressed properly, sealant applied to a damp surface, or water ponding against the kerb. We fit to the maker's instructions and check each of those points. The fitting carries a written workmanship guarantee, with its terms set out on your quote.

Got a unit waiting to go in, or need one sourced? Either way, start with your Portishead address and a couple of photos.

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

Loft roof windows in Portishead

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

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