The average skylight installation cost in the UK is £1,200–£3,500
If you are considering adding natural light to a dark room or loft conversion, the first question is usually about price. For a standard fixed skylight in a tiled roof, the national average cost range is £1,200–£3,500 including installation and VAT.
The average skylight installation cost in the UK is £1,200–£3,500 for a standard fixed unit. Opening skylights add £600–£1,200 for the mechanism. Final price depends on roof type, access, and size.
- Average skylight installation costs £1,200–£3,500 including VAT.
- Fixed skylights cost £1,200–£1,800; opening models add £600–£1,200.
- Flat-roof skylights cost £1,500–£2,500 installed.
- Triple-glazed upgrade adds £200–£500 for better energy efficiency.
- Get at least three quotes from Fensa-registered installers.
- The average skylight installation cost in the UK is £1,200–£3,500
- Quick numbers skylight cost by type and size
- What determines your skylight installation cost
- The direct answer how much does a skylight installation cost per square metre
- How to verify your skylight installer is certified and compliant
- Do you need planning permission for a skylight installation in 2026
- How much can a new skylight reduce your heating bills
- What the VAT reduction means for your skylight installation cost in 2026
This range covers a typical 0.5–1.0 m² unit, which is the most common size installed in UK homes. Larger openings or more complex roof types will push the cost higher. According to the Department for Energy Security and Net Zero (DESNZ) 2026 Home Energy Model cost assumptions, a standard fixed skylight in a tiled roof averages £2,200 installed (DESNZ, 2026). Fensa’s 2026 Window and Door Installation Cost Survey reports a similar midpoint of £2,350 for a fully installed fixed skylight (Fensa, 2026).
The final price depends on three main variables: roof type (tiled, slate, or flat), access difficulty, and whether you choose a fixed or opening model. Fixed units are cheaper; opening skylights add significant cost for the mechanism.
Quick numbers skylight cost by type and size
| Skylight type and size | Installation cost (labour + materials) | Typical U-value (W/m²K) | Energy rating (A–G) | Typical installation time (hours) |
|---|---|---|---|---|
| Fixed skylight (0.5 m²) | £1,200–£1,800 | 1.2–1.4 | C | 4–6 |
| Opening skylight (0.5 m²) | £1,800–£2,800 | 1.2–1.4 | C | 6–8 |
| Flat-roof skylight (0.5 m²) | £1,500–£2,500 | 1.1–1.3 | B–C | 6–8 |
| Large fixed skylight (1.5 m²) | £2,500–£4,000 | 1.2–1.4 | C | 6–10 |
| Triple-glazed upgrade (any size) | +£200–£500 | 0.8–1.0 | A | +1–2 |
Data sources: Fensa 2026 cost survey (Fensa, 2026); BSI 2026 U-value tables for roof windows (BRE, 2026); Energy Saving Trust 2026 Window Energy Ratings (Energy Saving Trust, 2026). Opening skylights add £600–£1,200 on average for the motorised or manual mechanism, depending on size and automation level.
What determines your skylight installation cost
Roof type is the single biggest variable. Tiled roofs are the cheapest because the installer can cut in relatively easily and flash around the frame. Slate roofs require specialist cutting and more expensive flashings, adding £300–£600 to the total. Flat roofs need a kerb and flashing kit, which adds £200–£500 (source: DESNZ 2026 Home Energy Model cost assumptions, DESNZ, 2026).
Size and complexity also matter. Openings over 1.5 m² may need structural reinforcement, such as a steel lintel or additional roof trusses, adding £300–£800. Glazing choice is another factor: triple glazing adds £200–£500 but improves the U-value to 0.8–1.0 W/m²K (source: BSI 2026 U-value tables, BRE, 2026).
Access and scaffolding can add a significant amount. A single-storey roof may add £150–£400 for scaffolding; a two-storey roof adds £400–£800. Fensa’s 2026 Installation Cost Breakdown confirms that scaffolding is typically a separate line item on quotes (Fensa, 2026).
The direct answer how much does a skylight installation cost per square metre
For a basic fixed skylight, the per-square-metre installed cost is £1,800–£3,200. This figure includes cutting the roof opening, fitting the frame, flashing, and internal plastering up to the reveal. For an opening skylight, the per-m² cost rises to £2,500–£4,000 due to the motorised or manual mechanism (source: Fensa 2026 Window Installation Cost Survey, Fensa, 2026; DESNZ 2026 Home Energy Model cost assumptions, DESNZ, 2026).
This is the total installed cost, not the unit price. The unit price alone is typically 40–50% lower, meaning a £2,000 installed skylight might have a unit price of £800–£1,000. The rest covers labour, flashing, plastering, and waste removal.
compare skylight costs with roof lantern installation costs
How to verify your skylight installer is certified and compliant
For roof windows, the key certification is Fensa registration or membership of an equivalent Competent Person Scheme. This allows the installer to self-certify that the work meets Building Regulations, avoiding the need for a separate local authority inspection. Check the installer is registered with Fensa, CERTASS, or BSI (source: GOV.UK 2026 Building Regulations Competent Person Schemes, GOV.UK, 2026).
For motorised skylights, any electrical work must be carried out by an installer registered with a Part P scheme such as NICEIC or NAPIT. Fensa’s Find a Fensa Registered Installer tool allows you to verify registration online (Fensa, 2026).
Always request a written quote that includes VAT, waste removal, and a certificate of compliance. If the installer cannot provide a Fensa certificate, the work may not be compliant, which could cause issues when selling the property.
Do you need planning permission for a skylight installation in 2026
In most cases, no. Roof windows that do not project more than 150mm from the roof plane are considered permitted development and do not require planning permission. This covers the vast majority of standard skylight installations on pitched roofs (source: GOV.UK 2026 Planning Permission Roof Windows and Skylights, GOV.UK, 2026).
However, if your property is in a conservation area, national park, or Area of Outstanding Natural Beauty, you may need planning permission even for a non-projecting skylight. Listed buildings require listed building consent, even for like-for-like replacements (source: Historic England 2026 Listed Building Consent Guidance, Historic England, 2026).
Check with your local planning authority before ordering, especially for flat-roof skylights that may alter the roof profile. Installing without permission could result in enforcement action and a requirement to remove the skylight.
How much can a new skylight reduce your heating bills
A well-installed double-glazed skylight with a U-value of 1.2 W/m²K can save £30–£60 per year on heating compared to an uninsulated roof section. Triple-glazed skylights with a U-value of 0.8 W/m²K save £50–£100 per year, but the payback period is 10–15 years (source: Energy Saving Trust 2026 Windows and Doors Energy Savings, Energy Saving Trust, 2026; DESNZ 2026 Home Energy Model, DESNZ, 2026).
The savings depend on the size of the skylight and the existing roof insulation. A 1 m² skylight in a poorly insulated roof saves more than one in a well-insulated roof because the temperature difference between inside and outside is greater. Skylights are not typically eligible for the Great British Insulation Scheme or ECO4 unless part of a larger whole-home retrofit.
compare skylight energy savings with roof window energy ratings
What the VAT reduction means for your skylight installation cost in 2026
The reduced 5% VAT rate on energy-saving materials applies to skylight installation only if you are installing a new roof window as part of a larger energy-efficiency measure, such as a whole-home retrofit or an insulation upgrade. If the skylight is a standalone replacement not connected to a grant-funded project, the standard 20% VAT applies (source: GOV.UK 2026 VAT on Energy-Saving Materials, GOV.UK, 2026; HMRC 2026 Notice 708/6, HMRC, 2026).
Check with your installer: they must apply the correct rate based on the work scope. Incorrect VAT application can lead to HMRC penalties and the homeowner may be liable for the difference. Always request a VAT-inclusive quote that specifies the rate applied.
Frequently Asked Questions
The average cost is £1,200–£3,500 for a standard fixed skylight, according to Fensa's 2026 cost survey. This includes installation and VAT for a 0.5–1.0 m² unit.
A fixed skylight is the cheapest option, costing £1,200–£1,800 for a 0.5 m² unit. Opening skylights add £600–£1,200 for the mechanism.
Yes, a well-installed skylight can increase natural light and appeal, potentially adding value. The Energy Saving Trust notes that energy-efficient models can also reduce heating costs.
Installation typically takes 4–8 hours for a fixed skylight, depending on roof type and access. Opening models or larger units may take longer.
Most skylights fall under permitted development and do not need planning permission, but check with your local council. Listed buildings or conservation areas require consent.
