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RooflightInstallers.co.uk
Windsor · SL4 · Berkshire

New rooflight in an existing roof in Windsor

Our guide price for new rooflight openings starts from £2,295, and the real figure for your roof in Windsor depends on a handful of things: the size and type of rooflight, whether the opening exists already, the roof covering, and how easy access is. We fix the price in a written quote before work begins. Nothing gets added on the day without your say-so. For a rough idea first, photos and a couple of measurements are enough to go on, and we cover all of Berkshire.

Guide price from £2,295 · Supply & fit, including structure and making good; building control or warrant fees extra

What the job costs in Windsor

Small fixed unit

£2,295 – £3,345including VAT at 20%

Opening cut, joists trimmed, upstand built, roof covering made good, plasterboard reveals ready for decoration

Medium fixed unit

£3,345 – £4,795including VAT at 20%

As the small unit, with a larger opening up to about 1 × 2 m and additional trimming

Large or opening unit

£4,795 – £7,795including VAT at 20%

Bigger structural work or an electric opening unit

Guide ranges for supply & fit, including structure and making good; building control or warrant fees extra. 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 Windsor and nearby

Our fitters come to you. For Windsor that covers SL4, SL3 and SL1, plus nearby Slough and Egham. 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

There are two ways to do this. Supply and fit means we source a new rooflight 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

  • Rooflight fitted, sealed and checked for even clearance on every side
  • Roof membrane, felt or tiles made good and dressed up the upstand
  • Survey of joist direction, roof build-up, ceiling void and access
  • Upstand energy performance — We build the upstand to meet the energy limit for site-built upstands, not just to hold the rooflight up.
  • Warm or cold roof build-up — We find out whether the roof is insulated above or between the joists before designing the upstand.

What happens on the day

Arrive and agree the plan. Sheet the floor and furniture. Set up the ladder, tower or scaffold. Check the opening, the upstand or flashing, and the unit against the paperwork. Fix and pack a new rooflight level. Seal it into the roof. Line the reveal or fit the ceiling trim. Clean the glass, clear the waste, and talk you through it. That is the shape of most fitting days, and for this type of job it usually takes two to three days.

Regulations for Windsor properties

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

Start with your phone. Take a picture of the roof where the unit goes or already sits, then one from inside looking up. Measure what you can, even roughly. Tell us what the roof is covered with and how a fitter would reach it: ladder, garden access or scaffold. Bought it already? Send the link or spec. Add your full postcode, for example in SL4, and we can price it.

Common questions in Windsor

Can you fit the rooflight 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.

What is included in the price?

The written quote lists it line by line. Typically that covers fitting labour, fixings, sealants, membrane or flashing materials, any upstand work, internal finishing if agreed, and taking away the waste. For supply and fit, the unit itself is included too. Scaffold, lifting gear and any third-party fees, where needed, are shown separately so you can see what each part of the job costs.

Do you cover Windsor?

Yes. Fitters travel to addresses in Windsor and the surrounding districts, including SL4. We do not run an office there; the survey and the fitting happen at your property. A few island and remote postcodes are covered by arrangement; if yours is one, we confirm travel and dates before quoting.

Send a few photos and your SL4 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

New openings in Windsor

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

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