The skylight installation cost in UK varies more than most people expect before they start researching. A small fixed rooflight on a straightforward flat roof can come in well under £500 all in. A large bespoke unit on a pitched roof with structural work involved can reach several thousand pounds. Understanding what drives that range and where the biggest variables sit - is what allows you to budget accurately rather than guess. This guide breaks down the cost to install a skylight in the UK from every angle: product prices, labour, roof type, glazing specification, and the extras that tend to catch people out.
Skylight Installation Cost in UK: The Two Parts of the Bill
Every skylight project has two distinct cost components: the unit itself (supply) and the labour to fit it (installation). These are usually quoted and invoiced separately, and the ratio between them shifts depending on the complexity of the installation. On a simple flat roof with an existing structural opening, labour can be modest relative to the product. On a pitched roof requiring new structural work, labour can easily exceed the cost of the unit.
Keeping these two numbers separate when comparing quotes is important. A contractor who supplies and fits the unit at a combined price may be using a cheaper product than a quote that itemises supply and fit separately. Always ask to see the product specification alongside any combined price.
Supply Costs: What Does the Skylight Unit Itself Cost?
Product prices vary considerably depending on type, size, glazing specification, and manufacturer. The table below gives a clear overview of typical supply-only price ranges across the main skylight categories available in the UK in 2026:
|
Skylight Type |
Entry Price (Supply Only) |
Mid-Range |
Premium/Large |
|
Fixed Flat Rooflight |
From £163 |
£400 to £800 |
£800 to £1,500+ |
|
Opening Flat Rooflight (Manual) |
From £350 |
£600 to £1,000 |
£1,000 to £2,000+ |
|
Opening Flat Rooflight (Electric) |
From £500 |
£800 to £1,500 |
£1,500 to £3,000+ |
|
Pitched Roof Window (Fixed) |
From £177 |
£400 to £700 |
£700 to £1,200+ |
|
Pitched Roof Window (Centre Pivot / Top Hung) |
From £280 |
£500 to £900 |
£900 to £1,800+ |
|
Roof Lantern (Flat Roof) |
From £695 |
£1,500 to £3,000 |
£3,000 to £8,000+ |
At Skylights Roof Lanterns, flat glass rooflights start from £163 for supply-only on standard sizes, with most fixed units for single-storey extensions falling in the £300 to £700 range depending on size and glazing specification. You can browse current prices across the full rooflights collection to compare options against your budget before requesting any quotes.
Labour Costs: What Does Installation Typically Cost in the UK?
Labour rates for skylight installation in the UK vary by region, roof type, and the scope of structural work required. As a broad guide for 2026:
A straightforward flat rooflight installation into an existing structural opening on a flat roof typically costs between £250 and £500 in labour. The roofer needs to cut the membrane, fit the upstand if not pre-fitted, seat the unit, and weatherproof the junction. On a well-prepared roof, this is a half-day job for an experienced installer.
Where the structural opening needs to be created -which means cutting through the roof deck, trimming joists, and forming the opening - add between £150 and £400 to the labour cost depending on the complexity. This is typically required when installing a rooflight into an existing extension that was built without one.
For pitched roof window installations, labour costs are generally higher. The work involves stripping roof tiles, cutting rafters where required, fitting a frame, re-tiling around the unit, and ensuring the flashing is correctly dressed. Expect between £400 and £900 in labour for a standard pitched roof window installation, more if rafter cutting is involved.
Electrician costs are an additional consideration for electric opening rooflights. A Part P-compliant electrical connection for a powered unit typically costs between £100 and £250 depending on the distance from the consumer unit and the complexity of the wiring route.
Total Installed Cost: Realistic All-In Figures
Combining supply and labour gives the following realistic all-in cost ranges for common skylight projects in the UK:
A small fixed flat rooflight installed into an existing opening on a flat roof: £420 to £900 all in. This covers a standard 600mm x 900mm or 1000mm x 1000mm unit with double glazing, supply and installation.
A medium flat rooflight with structural opening formation: £750 to £1,500 all in. This covers a 1000mm x 1500mm or 1000mm x 2000mm unit, structural opening, and installation on a flat roof.
An electric opening flat rooflight with rain sensor: £1,000 to £2,200 all in depending on size and whether structural work is required.
A standard pitched roof window installed into a loft conversion or bedroom roof: £700 to £1,800 all in depending on size, rafter work, and glazing specification.
A flat roof lantern on a new extension: £1,800 to £5,000+ all in depending on footprint and specification.
These figures are for mainland UK. London and the South East typically run 15 to 25 percent above these ranges. Scotland and parts of Northern England are often slightly below.
What Affects the Cost to Install a Skylight?
Roof type and condition
A flat roof in good condition with adequate falls and a sound membrane is the simplest and cheapest canvas for a skylight installation. A flat roof that needs repairs or re-waterproofing before the unit can be fitted adds cost. A pitched roof is more labour-intensive regardless of condition, and a badly maintained one with rotten or fragile tiles will add further to the bill.
Whether a structural opening needs to be formed
If you are adding a rooflight to an extension that was built without one, forming the structural opening is a significant cost driver. If the opening is already in place as it would be on a new build or a purpose-designed extension - this cost disappears entirely. Planning ahead at the extension build stage to include rooflight openings is the most cost-effective approach, as covered in the flat roof extension planning guide.
Glazing specification
Double glazed units are the standard and the most affordable option. Triple glazed units typically add 15 to 30 percent to the product cost but deliver meaningfully better thermal performance - often worth it for south or west-facing rooflights or where the room below is used as a primary living space. Optional extras such as solar control glass, self-cleaning coatings, and privacy frosting add further to the supply cost but reduce ongoing maintenance or improve comfort in specific situations.
Size and custom dimensions
Standard sizes are manufactured in higher volumes and are consistently cheaper and faster to supply than bespoke units. If your structural opening matches a standard size and in most well-planned projects it will - the cost saving over custom sizing is significant, both in product price and lead time. The standard rooflight sizes guide covers how to match your opening to a standard size before ordering.
Fixed vs opening
A fixed rooflight is always cheaper than an equivalent opening unit. The price gap between manual opening and fixed is typically £100 to £300 depending on the size. Electric opening units add a further £150 to £400 over manual, plus the electrician's cost. If ventilation is a priority - particularly in kitchen extensions — the investment in an opening unit is usually justified. Read the home ventilation guide for a fuller explanation of why opening rooflights are often the most effective ventilation upgrade available for a flat roof extension.
Location and access
Difficult access — a roof with no ground-level approach, a property in a tight urban plot, or a high or awkward installation position — adds to labour cost and time. Single-storey flat roofs are generally the most accessible. Steep-pitched roofs or multi-storey properties typically require scaffolding, which adds between £600 and £1,500 to the total project cost depending on the scale and duration.
Conclusion
Choose a standard size where possible. Custom dimensions cost more to supply and take longer to deliver. If your structural opening can be adjusted to match a standard size, the saving is worth it. Plan rooflight openings at the structural stage of any new build or extension work - retrofitting is always more expensive than building in. Get at least three installation quotes and ask each contractor to specify the product they are pricing.
For loft conversion projects specifically, the rooflights for loft conversions guide covers sizing requirements, building regulations, and the type of units that comply — all of which affect cost.
