Harrow · Greater London
Roof Lanterns in Harrow
Is the middle of your extension in Harrow too dark? A roof lantern or skylight brings in light that wall windows cannot reach.
- HA1
- HA2
- HA3
- HA5
- HA7
- Guide from £1,095
Roof lanterns in Harrow: what to know
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.
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.
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.
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.
Included as standard
- Removal and disposal of an old lantern or skylight
- Written guarantee terms and manufacturer documentation
- Fixing, glazing and sealing onto the prepared upstand
- Survey of the roof, opening, upstand and drainage

Harrow at a glance
- Postcodes covered
- HA1, HA2, HA3, HA5, HA7 and the surrounding area, including Wembley, Northolt and Greenford
- Coast
- Harrow is well inland, around 50 km from the nearest coast, so salt exposure is not usually a factor.
- Daylight and sun
- In Harrow 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 Harrow
| 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.
What you can choose
Solar-control glass
Neutral or blue-tinted coatings that reduce heat build-up under south or west-facing lanterns while keeping daylight levels high.
Frame colours
Powder-coated aluminium in grey, black, white or other RAL colours, often dual colour to suit the roof and the room.
Square or octagonal lantern
A pyramid or eight-sided design that suits square rooms, orangeries and spaces where a central focal point is wanted.
Roof Lanterns in Harrow: questions
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 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.
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.
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 Harrow for roof lanterns?
Yes. We can quote for roof lanterns across Harrow and the surrounding Greater London area, including postcode districts HA1, HA2, HA3, HA5 and HA7, and nearby Wembley, Northolt and Greenford. 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 Harrow
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.