Extensions & Conversions · Updated 2026
Skylight installation cost
Typical range£600–£12,000· Average flat roof skylight / rooflight installed
Fixed and opening skylight costs for 2025. In the UK, expect to pay between £600 and £12,000, with the typical project around £1,500 (average flat roof skylight / rooflight installed). Regional variation, specification tier and site access conditions all shift the final quote.
Quick answer: Skylight installation cost in the UK typically costs between £600 and £12,000 (Average flat roof skylight / rooflight installed). London and the South East run 20–35% above this range; the North, Wales and most of Scotland sit 5–15% below.
Homeowners researching this typically also price up velux window cost. For wider context, browse our bathroom pricing, kitchen pricing and boiler & heating costs.
Cost table
Indicative price ranges (UK, GBP)
| Item | Typical range (GBP) |
|---|---|
Fixed flat roof rooflight (600x900mm) — Double-glazed, aluminium frame | £600–£1,200 |
Opening flat roof skylight (1000x1500mm) — Electric opener, rain sensor | £1,200–£3,000 |
Roof lantern (1m x 2m) — Extension feature, structural | £2,500–£8,000 |
Roof lantern (2m x 3m) — Large extension or garden room | £5,000–£12,000 |
Labour costs
Labour typically accounts for 45% of the total project cost in the UK.
Labour line items
| Item | Typical range (GBP) |
|---|---|
Roofer / installation | £400–£1,200 |
Structural lintel (if needed) | £400–£1,000 |
Electrician (electric opener) | £150–£350 |
Internal finishing | £200–£600 |
Materials costs
Materials and fittings make up the remainder of the budget, with specification tier driving most of the variation.
Materials & fittings
| Item | Typical range (GBP) |
|---|---|
Fixed rooflight (600x900mm) | £300–£700 |
Electric rooflight | £700–£1,800 |
Roof lantern (aluminium, 1x2m) | £1,500–£4,000 |
Roof lantern (2x3m) | £3,000–£8,000 |
Factors affecting cost in the UK
- ·Region — London and the South East run 15–30% above national averages.
- ·Specification tier — premium materials and finishes can double the base cost.
- ·Access and site conditions — flats, restricted parking and listed buildings add time.
- ·Scope changes mid-project — late design decisions are the biggest cost overrun driver.
- ·Trade availability — quotes rise 10–20% in peak spring and summer months.
Ways to reduce cost
- ·Choose standard sizes from Velux, Fakro or Roto rather than bespoke roof lanterns.
- ·Install a fixed rather than opening unit where ventilation isn't needed.
- ·Combine install with a planned flat roof replacement to share roofer labour.
- ·Fit a single large skylight rather than multiple smaller ones — cheaper per m² of glass.
- ·Skip electric openers unless out of reach.
Frequently asked questions
- What is the difference between a rooflight and a skylight?
- These terms are often used interchangeably. A rooflight usually refers to a flat-roof-mounted unit (flush or slightly raised); a skylight often refers to units fitted into a pitched roof. Velux windows are technically rooflights for pitched roofs.
- Does a skylight require planning permission?
- A rooflight that doesn't protrude more than 150mm above the roof plane and is not on a front elevation is usually permitted development. Roof lanterns on extensions may require planning if they exceed certain heights.
- Do skylights cause heat loss?
- A quality triple-glazed rooflight or roof lantern has a U-value of 0.6–1.0 W/m²K, comparable to a good wall. Single glazed or low-spec units can cause significant heat loss. Always choose at least A-rated double glazing.