Keynsham · Somerset
Roof Lanterns in Keynsham
We cover Keynsham and the rest of Somerset for roof lantern supply and fitting, from small skylights over landings to large lanterns for open-plan kitchens.
- BS31
- Guide from £1,095
Roof lantern replacement across Keynsham
The Rooflight Association recommends laminated glass for the inner pane of glass rooflights, because laminated glass stays bonded together if it breaks instead of dropping fragments into the room below. Toughened inner panes are still used, but laminated is the safer choice over kitchens, stairs and seating areas.
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.
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.
Opening skylights and lantern vents can be manual or electrically operated, often with a rain sensor that closes them automatically when it starts to rain. Electric vents need a power supply planned before plastering, so the wiring route is agreed at survey when an opening option is chosen.
What a typical job includes
- Written guarantee terms and manufacturer documentation
- Fixing, glazing and sealing onto the prepared upstand
- Removal and disposal of an old lantern or skylight
- Survey of the roof, opening, upstand and drainage

Working in Keynsham
- Postcodes covered
- BS31 and the surrounding area, including Kingswood, Mangotsfield and Bristol
- Coast
- Keynsham sits roughly 19 km from the nearest coastline, close enough that exposure on open or high ground is worth considering. 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 Keynsham the midwinter sun reaches about 15° above the horizon at noon, with roughly 7.6 hours of daylight, rising to about 62° and 16.4 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 Keynsham
| 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
Approved Document L sets the minimum energy performance for replacement windows and doors in existing homes in England: a U-value of 1.4 W/m²K, or Window Energy Rating band B for windows; doors can instead meet a Door Set Energy Rating (band B, or band C for doors more than 60% glazed); rooflights need 2.2 W/m²K.
Options to choose between
Square or octagonal lantern
A pyramid or eight-sided design that suits square rooms, orangeries and spaces where a central focal point is wanted.
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 Keynsham: questions
Do I need planning permission for a roof lantern?
Sometimes. In England, rooflights on a house are usually permitted development if they project no more than 150mm above the roof plane and are no higher than the highest part of the roof. Raised lanterns often exceed that, and flats, listed buildings and conservation areas have extra controls, so check with your council first.
Will a roof lantern make my room too hot?
A roof lantern can add heat on sunny days, especially facing south or west, because overhead glass receives sun for much of the day. Solar-control glass, opening vents and blinds help keep the room comfortable. The glass is chosen at survey based on the lantern's size and orientation and how the room is used.
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.
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.
Do you cover Keynsham for roof lanterns?
Yes. We can quote for roof lanterns across Keynsham and the surrounding Somerset area, including postcode districts BS31, and nearby Kingswood, Mangotsfield and Bristol. 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 Keynsham
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.