Lancaster · Lancashire
Roof Lanterns in Lancaster
If your skylight in Lancaster drips with condensation or leaks around the frame, we can survey it and quote for a modern, thermally broken replacement.
- LA1
- LA3
- LA4
- Guide from £1,095
Flat roof skylight in Lancaster: what to know
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.
The price of a roof lantern or skylight depends on the size and shape, glass specification, frame colour, opening vents or electric operation, and whether the upstand already exists or needs building. Access to the roof and lifting large units add labour. See the guide prices for typical ranges.
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.
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.
What you get
- Made-to-measure aluminium roof lantern or framed skylight
- Fixing, glazing and sealing onto the prepared upstand
- Removal and disposal of an old lantern or skylight
- Written guarantee terms and manufacturer documentation

Working in Lancaster
- Postcodes covered
- LA1, LA3, LA4 and the surrounding area, including Morecambe, Fleetwood and Thornton-Cleveleys
- Coast
- Lancaster is about 5 km from the coast or a tidal estuary, so salt air and wind-driven rain are worth planning for. 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 Lancaster the midwinter sun reaches about 12° above the horizon at noon, with roughly 7.1 hours of daylight, rising to about 59° and 16.9 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 Lancaster
| 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
In England, replacing a whole window, roof window or glazed external door is building work. It has to be notified to building control, either by an installer registered with a competent person scheme such as FENSA or Certass, or through a building notice to the council. Replacing only the glass in an existing frame is a repair and is not notifiable.
Options to choose between
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.
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 Lancaster: questions
Should the inner glass in a roof lantern be laminated?
Laminated inner glass is the safer choice and is recommended by the Rooflight Association. If a laminated pane breaks, the interlayer holds the pieces together, so glass is far less likely to fall into the room below. This matters most over kitchens, dining tables, stairs and seating, and it is offered as a standard option.
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.
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.
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.
Do you cover Lancaster for roof lanterns?
Yes. We can quote for roof lanterns across Lancaster and the surrounding Lancashire area, including postcode districts LA1, LA3 and LA4, and nearby Morecambe, Fleetwood and Thornton-Cleveleys. 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 Lancaster
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.