Fit-onlySupply & fitReplacementsTrade fitting
Fitting teams across England, Wales, Scotland & NI · Call 0800 088 6248
RooflightInstallers.co.uk
Isleworth · TW7 · Greater London

Loft conversion roof windows in Isleworth

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 Isleworth and across Greater London, 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

Isleworth 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.

Fitting across Isleworth and nearby

Distance is rarely the deciding factor. A roof in Hounslow, 1 mile from Isleworth, gets the same survey, the same written quote and the same fitting process as one in TW7, TW3 and TW5. What changes the price is the job itself: size of unit, roof type, access and lifting. Heston, around 2 miles out, is treated the same way.

Your loft roof windows or ours

There are two ways to do this. Supply and fit means we source a loft roof window that suits your roof and install it, so one company answers for both the product choice and the fitting. Fit-only means you buy the unit and we install it. With fit-only, the product warranty stays with the maker or seller, and our written guarantee covers the fitting work. Both routes get the same checks on the opening, the upstand and the maker's instructions before anything is fixed.

On the day, we cover

  • Matching or combination flashing kits for windows side by side
  • Linings fitted, ready for the plasterboarder or decorator
  • Window positions set out on the slope to line up inside and out
  • Fitting stage and weather — We plan when the windows go in around the rest of the conversion.
  • Energy performance in a loft — We check every window meets the energy limit for roof windows in existing homes.

From arrival to clean-up

Morning first: the team arrives, introduces itself and walks through the job with you. Dust sheets go down in the room below and along the route in. Then the opening and upstand, or the flashing on a pitched roof, are checked against the unit's measurements. A loft roof window goes in, is fixed to the maker's pattern and sealed into the roof covering. Inside, the reveal is finished as quoted. Before leaving, the team clears debris and talks you through what was done. Most jobs of this type take one to two days.

Planning and building rules in England

Two sets of rules matter in England. Planning: a rooflight on a house is normally permitted development if it projects no more than 0.15 m and stays below the highest part of the roof, but flats, listed buildings and Article 4 areas need checking. Building regulations: new openings need approval for the structure and energy performance, and a replacement is a controlled fitting. We are not registered with a competent person scheme, so we notify replacements to building control with a building notice and put the council's fee on the quote.

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, TW7 or nearby, confirms travel.

Common questions in Isleworth

What if my roof opening is the wrong size for the loft roof window?

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.

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.

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.

Send a few photos and your TW7 postcode, and we will put together a written quote for the job.

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

Loft roof windows in Isleworth

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

CallGet a quote