Guildford · Surrey
Roof Lanterns in Guildford
If your skylight in Guildford drips with condensation or leaks around the frame, we can survey it and quote for a modern, thermally broken replacement.
- GU1
- GU2
- GU4
- Guide from £1,095
Guildford: flat roof skylight
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.
A roof lantern is assembled from an aluminium ridge, hip bars and glazing bars that hold sealed glass units on each pitch. It sits on an upstand built around the roof opening. The upstand should be level, weathered into the roof covering and insulated, because a poor upstand causes most leaks and cold spots.
In England, Approved Document L sets a limiting U-value of 2.2 W/m²K for rooflights, calculated in the horizontal position, for both new and existing homes. A kerb or upstand built on site should achieve 0.35 W/m²K or better. Ask for the lantern's declared horizontal U-value, not a vertical figure.
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.
Included as standard
- Made-to-measure aluminium roof lantern or framed skylight
- Written guarantee terms and manufacturer documentation
- Fixing, glazing and sealing onto the prepared upstand
- Removal and disposal of an old lantern or skylight
Guildford at a glance
- Postcodes covered
- GU1, GU2, GU4 and the surrounding area, including Godalming, Woking and Aldershot
- Coast
- Guildford is well inland, around 48 km from the nearest coast, so salt exposure is not usually a factor.
- Daylight and sun
- In Guildford 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
- Getting a large lantern onto a terraced flat roof may mean carrying it through the house or lifting it over neighbouring property, so access is planned at survey. Lanterns near a boundary raise fire performance questions, and conservation areas may restrict raised glazing.
- 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 Guildford
| 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 F covers ventilation. Replacing windows should not leave a room with worse background ventilation than before, which is why replacement windows often include trickle vents.
Choosing your roof lanterns
Frame colours
Powder-coated aluminium in grey, black, white or other RAL colours, often dual colour to suit the roof and the room.
Opening vents
Manual or electric vents in the lantern or skylight, with optional rain sensors that close them automatically in wet weather.
Solar-control glass
Neutral or blue-tinted coatings that reduce heat build-up under south or west-facing lanterns while keeping daylight levels high.
Roof Lanterns in Guildford: questions
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.
Why does my roof lantern get condensation?
Condensation forms when warm, moist air from cooking, bathing or drying clothes meets the colder glass and frames at high level. Older single glazed or non thermally broken lanterns suffer most. Thermally broken frames, warm-edge spacers, extractor fans and opening vents reduce it. Some condensation on very cold mornings is normal and clears as the room warms.
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.
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.
Do you cover Guildford for roof lanterns?
Yes. We can quote for roof lanterns across Guildford and the surrounding Surrey area, including postcode districts GU1, GU2 and GU4, and nearby Godalming, Woking and Aldershot. 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 Guildford
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.