Crawley · West Sussex
Roof Lanterns in Crawley
Is the middle of your extension in Crawley too dark? A roof lantern or skylight brings in light that wall windows cannot reach.
- RH10
- RH11
- Guide from £1,095
Opening skylights across Crawley
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.
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, 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.
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.
What you get
- Fixing, glazing and sealing onto the prepared upstand
- Made-to-measure aluminium roof lantern or framed skylight
- Survey of the roof, opening, upstand and drainage
- Sealed double glazed units with laminated inner pane options

Crawley at a glance
- Postcodes covered
- RH10, RH11 and the surrounding area, including Horley, Horsham and East Grinstead
- Coast
- Crawley is well inland, around 31 km from the nearest coast, so salt exposure is not usually a factor.
- Daylight and sun
- In Crawley the midwinter sun reaches about 15° above the horizon at noon, with roughly 7.7 hours of daylight, rising to about 62° and 16.3 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 Crawley
| 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.
What you can choose
Flat framed skylight
A low-profile framed rooflight on a flat roof upstand, fixed or opening, for bathrooms, landings and smaller rooms.
Square or octagonal lantern
A pyramid or eight-sided design that suits square rooms, orangeries and spaces where a central focal point is wanted.
Opening vents
Manual or electric vents in the lantern or skylight, with optional rain sensors that close them automatically in wet weather.
Roof Lanterns in Crawley: questions
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.
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.
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.
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.
Do you cover Crawley for roof lanterns?
Yes. We can quote for roof lanterns across Crawley and the surrounding West Sussex area, including postcode districts RH10 and RH11, and nearby Horley, Horsham and East Grinstead. 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 Crawley
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.