Thamesmead · Greater London
Roof Lanterns in Thamesmead
Old polycarbonate lanterns in Thamesmead that leak, rattle or have yellowed can usually be replaced with a double glazed aluminium lantern on a sound upstand.
- SE28
- SE2
- DA18
- Guide from £1,095
Opening skylights in Thamesmead
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, 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.
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.
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.
What you get
- Fixing, glazing and sealing onto the prepared upstand
- Survey of the roof, opening, upstand and drainage
- Removal and disposal of an old lantern or skylight
- Written guarantee terms and manufacturer documentation

About Thamesmead for this job
- Postcodes covered
- SE28, SE2, DA18 and the surrounding area, including Barking, Welling and Becontree
- Coast
- Thamesmead sits roughly 18 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 Thamesmead 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 Thamesmead
| 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
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.
Options to choose between
Solar-control glass
Neutral or blue-tinted coatings that reduce heat build-up under south or west-facing lanterns while keeping daylight levels high.
Square or octagonal lantern
A pyramid or eight-sided design that suits square rooms, orangeries and spaces where a central focal point is wanted.
Frame colours
Powder-coated aluminium in grey, black, white or other RAL colours, often dual colour to suit the roof and the room.
Roof Lanterns in Thamesmead: 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.
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 much does a roof lantern cost?
The cost of a roof lantern depends on its size and shape, the glass specification, frame colour, any opening vents, and whether the upstand exists or needs building. Access to the roof and lifting a large lantern also affect labour. See the guide prices for typical ranges; the written quote fixes the price for your exact specification.
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.
Do you cover Thamesmead for roof lanterns?
Yes. We can quote for roof lanterns across Thamesmead and the surrounding Greater London area, including postcode districts SE28, SE2 and DA18, and nearby Barking, Welling and Becontree. 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 Thamesmead
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.