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Penzance · TR18 · Cornwall

Flat rooflight installation in Penzance

Rooflight work is weather work. Membranes, primers and sealants all want a dry surface, so a fitting day in Penzance is planned around the forecast rather than pinned to a date regardless of rain. The opening is kept covered whenever it is exposed, and a roof is not left open overnight without a proper temporary seal. That approach applies to every flat rooflight we install, from a new opening to a straight swap or a fit-only job. We cover Penzance, the TR18 district and the rest of Cornwall.

Guide price from £995 · Supply & fit

Guide prices in Penzance

Small fixed

£995 – £1,495including VAT at 20%

Double-glazed fixed unit up to 1000 × 1000 mm, fitted to a ready upstand

Medium fixed

£1,495 – £2,295including VAT at 20%

1000 × 1500 to 1000 × 2000 mm, double or triple glazed

Large fixed

£2,295 – £4,095including VAT at 20%

Bigger units, solar-control glass, two-person lift or lifting gear

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 Penzance and nearby

Penzance and the districts around it, TR18, TR20 and TR17, all sit inside our working area. So does the ground between Penzance and Camborne (12 miles), and on towards Redruth (16 miles). When a fitting team is booked, their travel is already in the quoted price, so it does not turn up as a surprise line on the final bill.

Fit-only or supply and fit

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

What we do on the day

  • Membrane, felt or GRP finished to the frame the way the maker shows
  • Fall confirmed so rain runs off the glass rather than sitting on it
  • Upstand checked or built to the maker's internal and external sizes
  • Ceiling and reveal depth — We measure the depth from the kerb top to the ceiling to plan the reveal.
  • Pitch of the glass — We make sure the glass will sit at the pitch its maker asks for.

How a fitting day runs

Where a job takes one day, the split is usually structural work first and finishing second. Early on, the fitters cut or prepare the opening, trim where needed and prepare the upstand or flashing. Then a flat rooflight is lifted in, fixed and made weathertight so the roof is sound before anyone moves inside. Plasterboard, trim and filler for the reveal come after. Each evening the work area is swept, and at the end the glass is cleaned and the team talks you through what was done.

Do you need permission in Penzance?

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.

Before you get in touch

Keep it simple. Two or three photos, outside and inside. Approximate sizes. What the roof is made of. Anything awkward about getting up there, such as a conservatory below, a narrow side path or no parking. If you bought the rooflight online, the link or model name. Then your postcode in or around TR18. That is enough for a first price.

Common questions in Penzance

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.

Do I need planning permission for a rooflight in Penzance?

Often not. Many rooflights fall under permitted development, provided they do not project beyond the national limit and meet the other conditions that apply in England. Conservation areas, listed buildings and some flats are different and may need consent. Because the rules depend on the property, we confirm what is likely to apply at your address and point you to the planning authority where an application is needed.

Can you replace an old dome without redoing the whole roof?

Usually, yes. If the existing kerb is sound, level and tall enough, a new unit can often sit on it with a fresh seal to the roof covering. If the kerb is rotten or too low, we rebuild it and patch the covering around it rather than stripping the whole roof. This is checked at the survey and included in the written quote, so you know the full scope first.

Send a few photos and your TR18 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

Flat rooflights in Penzance

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

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