Cornwall · England
Roof Lanterns in Cornwall
Our glaziers fit roof lanterns across Cornwall, glazing and sealing each unit onto its upstand and explaining any building regulations approval the work needs.
- Guide from £1,095
- 11 towns covered
- Postcode areas EX, PL, TR
About roof lanterns in Cornwall
Cutting a new opening for a roof lantern or skylight usually means trimming joists or rafters, so the roof can carry the load around the hole. Building regulations approval is generally needed for a new rooflight, covering structure, energy performance and, near a boundary, fire performance.
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.
Roof lanterns are not designed to be walked on, so never stand or lean on the glass or bars. Cleaning and inspection should be done from safe access at the edge of the roof. Keep leaves and debris away from the upstand and roof outlets so water drains freely.
Glass for lanterns usually comes with a self-cleaning outer coating that helps rain wash away dirt, and a choice of clear, neutral or blue-tinted solar-control glass. Solar-control glass limits heat build-up under a south-facing lantern, while clear low-E glass suits shaded or north-facing rooms.

What applies in Cornwall
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.
If the glass sits in a fire-resisting door or screen, such as a flat entrance door or a commercial corridor screen, it must be replaced with fire-rated glazing tested as part of that system. Ordinary toughened glass is not a substitute.
Cornwall has its own coastline, so for homes and businesses near the sea, salt air and wind-driven rain are part of the brief. 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.
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.
Guide prices
| 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 |
Choosing your roof lanterns
Opening vents
Manual or electric vents in the lantern or skylight, with optional rain sensors that close them automatically in wet weather.
Flat framed skylight
A low-profile framed rooflight on a flat roof upstand, fixed or opening, for bathrooms, landings and smaller rooms.
Solar-control glass
Neutral or blue-tinted coatings that reduce heat build-up under south or west-facing lanterns while keeping daylight levels high.
Rectangular hipped lantern
A long ridge with hipped ends, suiting most rectangular extensions and kitchens, sized to the opening and the room below.
Roof Lanterns in Cornwall: questions
Does fitting a roof lantern need building regulations approval?
A new roof lantern or skylight generally needs building regulations approval, because the roof structure is cut and must be supported, and the unit must meet energy standards. Fire performance also matters near a boundary. Replacing a lantern on an existing sound upstand is simpler, and we explain which route applies at survey.
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.
Can I replace my old polycarbonate roof lantern with glass?
Yes, in most cases. A glass lantern is heavier than polycarbonate, so the upstand and roof structure must be able to carry it. If the upstand is sound, level and the right size, a new aluminium lantern can usually sit on it. If not, the upstand is rebuilt first, which the survey will identify.
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.
Which parts of Cornwall do you cover for roof lanterns?
We cover the whole of Cornwall, including Redruth, Falmouth, St Austell, Truro and Camborne, and postcode areas EX, PL, TR. Building rules for roof lanterns here follow the regulations for England. Enter your postcode on the quote form and we will confirm cover; then a glazier will arrange a free survey before giving you a written quote.
Other glazing services in Cornwall
- Replacement Glass in Cornwall
- Misted Glass Repair in Cornwall
- Emergency Glazing in Cornwall
- Safety Glass in Cornwall
- Window Repairs in Cornwall
- Window Film in Cornwall
- uPVC Windows in Cornwall
- Aluminium Windows in Cornwall
- Sash Windows in Cornwall
- Composite Doors in Cornwall
- Bifold Doors in Cornwall
- Sliding Doors in Cornwall
- Secondary Glazing in Cornwall
- Glass Balustrades in Cornwall
- Frameless Glass in Cornwall
- Shower Screens in Cornwall
- Glass Splashbacks in Cornwall
- Bespoke Mirrors in Cornwall
- Glass Roofs in Cornwall
- Shopfront Glazing in Cornwall
- Curtain Walling in Cornwall
- Glass Partitions in Cornwall
- Property Glazing in Cornwall
All glazing in Cornwall · Roof Lanterns & Skylights across the UK
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