Large roof lanterns in Dorset
Buy large roof lanterns for homes and building projects anywhere in Dorset. See guide prices below, then get a fixed written quote for your size, glass and colours.
Get a price in Dorset
Send your postcode and kerb size for a fixed written quote.
Choosing large roof lanterns in Dorset
Lanterns of three metres and more for open-plan extensions, with intermediate rafters.
Across Dorset, the shortest day brings around 7h 57m of daylight and the midsummer sun reaches about 62.7° at noon. A lantern collects light from the bright overhead sky all year, and the right glass keeps the long summer days comfortable.
- Lengths from about three to six metres
- Delivered as a frame kit with glass
- Solar-control glass recommended
- Intermediate rafters carry the larger glass
Delivery and fitting in Dorset
Delivery to mainland addresses here is quoted for your postcode and confirmed in writing before you order.
Fitting can be quoted where we have cover; send your postcode and photos of the roof and kerb and we will confirm before quoting.
Large roof lantern prices
What large roof lanterns cost in common sizes (guide, inc VAT, supply only):
| Kerb size | Roof area | Guide price | Configure |
|---|---|---|---|
| 1500 × 3000 mm | 4.50 m² | £2,595–£2,995£2,162 ex VAT from | Configure |
| 2000 × 3000 mm | 6.00 m² | £3,195–£3,695£2,662 ex VAT from | Configure |
| 2000 × 4000 mm | 8.00 m² | £4,095–£4,795£3,412 ex VAT from | Configure |
| 2500 × 4000 mm | 10.00 m² | £4,895–£5,695£4,079 ex VAT from | Configure |
| 3000 × 4000 mm | 12.00 m² | £5,695–£6,595£4,746 ex VAT from | Configure |
Guide prices include VAT at 20%, supply only, aluminium with self-cleaning double glazing in a stock colour. Your fixed price is confirmed in writing on your quote before you order.
Planning and building regulations in Dorset
In England, building regulations energy guidance sets a limiting U-value of 2.2 W/m²K for new and replacement rooflights in existing homes, measured horizontally.
Planning-wise, a lantern on a new extension is judged as part of that extension, while one added to an existing roof can fall outside permitted development if it stands more than 150 mm proud.
Building regulations are checked by your local authority building control team or a registered building control approver. Replacing a rooflight in an existing home is building work. Installers registered with a competent person scheme can self-certify; otherwise building control must be involved.
Sources: Approved Document L, GOV.UK · Planning Portal
Large roof lanterns in Dorset: questions
What is the biggest roof lantern you can supply?
It depends on the range. Some go to about 6 m by 4 m with intermediate rafters. Send us your kerb size and we will confirm what can be made.
Do large lanterns overheat a room?
A large area of south-facing glass can make a room warm on sunny days. Solar-control glass, an opening vent and good background ventilation all help. Our guide on overheating explains the options.
Does a large lantern need structural calculations?
The roof structure around it usually does. Your engineer or building control body will want the lantern's weight and the opening size.
How quickly can I get a roof lantern in Dorset?
Stock sizes are typically ready in 5–10 working days, made-to-measure in 3–4 weeks, plus delivery. Your quote gives the date for Dorset.