St Austell · Cornwall
Roof Lanterns in St Austell
Old polycarbonate lanterns in St Austell that leak, rattle or have yellowed can usually be replaced with a double glazed aluminium lantern on a sound upstand.
- PL25
- Guide from £1,095
Flat roof skylight for homes and businesses in St Austell
Old polycarbonate or single glazed roof lanterns can be replaced with double glazed aluminium lanterns on the existing upstand, if the upstand is sound, level and the right size. Upstands that are rotten, uninsulated or out of level should be rebuilt first, which the survey identifies.
In England, a rooflight on a house is usually permitted development if it projects no more than 150mm beyond the roof plane and is no higher than the highest part of the roof. Raised lanterns often stand taller than that, so check with the council before ordering.
Warm, moist air rises and collects in a roof lantern, so condensation can form on cold winter mornings, especially over kitchens and bathrooms. Thermally broken frames, warm-edge spacers and good room ventilation reduce it, and opening vents in the lantern can release warm air in summer.
The price of a roof lantern or skylight depends on the size and shape, glass specification, frame colour, opening vents or electric operation, and whether the upstand already exists or needs building. Access to the roof and lifting large units add labour. See the guide prices for typical ranges.
What's included
- Removal and disposal of an old lantern or skylight
- Written guarantee terms and manufacturer documentation
- Fixing, glazing and sealing onto the prepared upstand
- Sealed double glazed units with laminated inner pane options

St Austell at a glance
- Postcodes covered
- PL25 and the surrounding area, including Bodmin, Truro and Newquay
- Coast
- St Austell is about 1 km from the coast or a tidal estuary, so salt air and wind-driven rain are worth planning for. Coastal lanterns face salt deposits on the glass and frames and strong uplift from wind on exposed roofs. Marine-grade coatings, stainless fixings and secure fixing to a well-built upstand matter, and salt film may need rinsing more often than self-cleaning glass manages alone.
- Daylight and sun
- In St Austell the midwinter sun reaches about 16° above the horizon at noon, with roughly 7.8 hours of daylight, rising to about 63° and 16.2 hours in midsummer. Overhead glazing receives far more light than a wall window of the same size, especially when the sun is high in summer. South-facing lanterns may need solar-control glass, while low winter sun and north-facing rooms benefit from clear, high light-transmission low-E glass.
- Access and setting
- Rural roofs collect more leaves, moss and bird debris, so lanterns need clear upstand drainage and regular checks. Exposed sites see higher wind loads and driving rain, and older outbuildings may need the roof structure strengthening before a lantern is added.
- Rules in England
- Approved Document K requires safety glass in critical locations in England: glazing in doors and in side panels within 300 mm of a door, up to 1500 mm above floor level, and any glazing in walls or partitions up to 800 mm above floor level.
Guide prices in St Austell
| Typical job | Guide price inc VAT |
|---|---|
| Lantern 1500 × 1000 mm, fitted to a kerb | £1,395 – £1,795 |
| Lantern 2000 × 1000 mm | £1,695 – £2,095 |
| Lantern 3000 × 1500 mm | £2,795 – £3,695 |
| Flat glass rooflight 1000 × 1000 mm | £1,095 – £1,395 |
Get a guide price for your size
In England, replacing a whole window, roof window or glazed external door is building work. It has to be notified to building control, either by an installer registered with a competent person scheme such as FENSA or Certass, or through a building notice to the council. Replacing only the glass in an existing frame is a repair and is not notifiable.
Specification choices
Flat framed skylight
A low-profile framed rooflight on a flat roof upstand, fixed or opening, for bathrooms, landings and smaller rooms.
Square or octagonal lantern
A pyramid or eight-sided design that suits square rooms, orangeries and spaces where a central focal point is wanted.
Opening vents
Manual or electric vents in the lantern or skylight, with optional rain sensors that close them automatically in wet weather.
Roof Lanterns in St Austell: questions
How long does it take to fit a roof lantern?
Fitting a roof lantern on a prepared upstand usually takes a day or less for a typical size, longer for large or complex shapes. The lantern is made to order first, and the lead time depends on its size, shape and colour. Building or rebuilding an upstand is separate roofing work that comes before fitting.
How do I clean a roof lantern?
Self-cleaning coated glass lets rain lift most dirt, but a rinse with clean water in long dry spells helps. Clean from a safe position at the roof edge or from a suitable platform, never by standing on the lantern. Wipe the inside glass with mild soapy water, and keep leaves clear of the upstand and roof outlets.
What guarantee comes with a roof lantern?
Manufacturer guarantees apply to the frame, coating and sealed units, and the terms are confirmed in writing. The upstand and roof covering may be covered separately, depending on who builds them. Guarantee terms for the installation are set out in writing with your quote, so you know exactly what is covered before going ahead.
Should the inner glass in a roof lantern be laminated?
Laminated inner glass is the safer choice and is recommended by the Rooflight Association. If a laminated pane breaks, the interlayer holds the pieces together, so glass is far less likely to fall into the room below. This matters most over kitchens, dining tables, stairs and seating, and it is offered as a standard option.
Do you cover St Austell for roof lanterns?
Yes. We can quote for roof lanterns across St Austell and the surrounding Cornwall area, including postcode districts PL25, and nearby Bodmin, Truro and Newquay. Start with your postcode on the quote form and a glazier will arrange a free survey before giving you a written quote.
Get a written quote in St Austell
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.