What are dome rooflights?
A dome rooflight is a moulded plastic dome — usually polycarbonate or acrylic, single to quadruple skin — on an upstand on a flat roof. Domes are economical, light and tough, and remain common on schools, flats and commercial roofs.
Many older domes have yellowed, cracked or lost their seal. Replacing the dome, or the dome and upstand, is often a quick fix for leaks and poor light.
Where the budget allows, swapping a dome for a flat glass rooflight gives a clearer view and better thermal performance.
- Typical sizes
- 600 × 600 mm to 1800 × 1800 mm
- Material
- Polycarbonate or acrylic
- Skins
- Twin to quad
- Upstand
- PVC, GRP or timber
- Fitting time
- 1–3 hours per dome on a sound upstand
- Typical lead time
- 1–3 weeks from order
Why choose dome rooflights?
- Low cost per unit
- Light, impact-resistant domes
- Fixed, hinged or vented options
- Quick replacement on existing upstands
- Suits schools, flats and commercial roofs
- Smoke-vent versions available
What options are there?
- Polycarbonate or acrylic
- Twin, triple or quad skin
- Clear, opal or tinted
- Fixed or hinged with vent
- Insulated PVC or GRP upstands
- Fall-through protection mesh
What should you check before you order?
- Old domes may be fragile — treat as fragile until checked
- Upstand condition decides whether you replace dome only or the whole unit
- Plastic domes have a lower acoustic and thermal performance than glass
- Fire classification matters on some roofs
Planning and building-regulation rules differ between England, Wales, Scotland and Northern Ireland. Our planning guide and building regulations guide set out each nation's position.
How much do dome rooflights cost?
| Option | Guide price inc VAT | Ex VAT |
|---|---|---|
| Dome and new insulated upstand | £955 – £1,675 | £795 – £1,395 |
| Hinged or vented dome Typical | £715 – £1,195 | £595 – £995 |
| Replacement fixed dome | £475 – £835 | £395 – £695 |
Guide prices per dome, supplied and fitted. Your fixed price follows a free survey for new installations.
Dome rooflights: common questions
Should I replace a dome or switch to glass?
A dome is cheaper and quick; glass gives a clear view and better performance. On a tight budget, or a commercial roof with many units, domes remain sensible.
Why has my dome gone yellow?
UV breaks down older plastics over time. Modern domes have UV-protective layers, but all plastics age.
Can you replace just the dome?
Yes, if the upstand is sound and the size matches. Otherwise we replace both.
Are domes safe to walk on?
No. Treat any rooflight as fragile unless it is specifically certified non-fragile, and never stand on it.
Do domes leak?
Leaks are usually at the upstand seal or the membrane. Replacing the dome and resealing often fixes it.
Can domes open?
Hinged and vented domes are available, manual or electric.
