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“Skylight” covers four quite different products, and choosing well is mostly about matching the product family to your roof and room — before you ever compare brands. Here’s the UK field in 2026, with costs, and how to pick.

The four families

1. Roof windows (pitched roofs). Opening, weather-rated windows fitted in the slope of the roof — what most Brits mean by “a Velux”. The default for lofts and any pitched-roof room. Made by VELUX and several credible rivals, in manual, electric and solar versions. From ~£650 fitted; full price breakdown here.

2. Flat-roof skylights. Sealed glazed units on an insulated upstand — the standard way to light kitchen extensions and flat-roofed rooms. Fixed units are cheapest; opening (usually electric) versions handle ventilation. Standard sizes are affordable; made-to-measure gets expensive fast.

3. Roof lanterns. A pitched glazed structure sitting proud of a flat roof, adding height and architectural drama over dining and kitchen spaces. Pricier than flat glass for the same opening, and a style statement as much as a light source.

4. Sun tunnels. A roof-mounted collector piping daylight down a reflective tube to a ceiling diffuser — the answer for windowless hallways, bathrooms and walk-in wardrobes where a full skylight is impossible. Cheap, effective, underused.

What they cost fitted (2026)

ProductTypical installed cost
Pitched roof window£900–£2,500 (small manual from ~£650)
Flat-roof skylight£1,000–£3,000
Roof lantern£2,000–£5,000+
Sun tunnel£500–£1,200

Component-level detail — labour rates, flashing, scaffolding, the lot — is in our installation cost guide, or get a configured range from the cost calculator. The short version: the glass is only half the bill, and access (scaffolding) is the surprise line item.

Choosing: roof first, room second, brand last

Your roof decides the family. Pitched roof → roof window. Flat roof → flat glass skylight or lantern. No practical roof access at all → sun tunnel.

Your room decides the spec. Moisture rooms (kitchens, bathrooms) need opening units and moisture-proof finishes. Bedrooms want blackout blinds and quieter glazing — rain on a roof window is romantic until 3am. South-facing rooms need solar-control glazing or awnings against summer overheating; north-facing glazing gives the soft, even light architects favour. Rooms you sleep or work in justify the glazing upgrade; landings don’t.

Brand comes last. For roof windows the VELUX-or-alternative question is real but secondary — a well-fitted budget window beats a badly fitted premium one. For flat-roof products, the installer’s upstand and waterproofing detail matters more than whose glass sits on top.

The practicalities

Planning permission usually isn’t needed — permitted development covers most skylights in houses (150mm projection limit; flats, listed buildings and conservation areas excepted). Building regulations always apply to a new opening; use a competent-person-scheme installer and it’s handled. Expect a straightforward roof-window install to take a day; flat-roof and lantern projects run longer with structural work. And whatever you buy, it should last 20–30 years — so buy for the room you’ll live in, not the cheapest quote.

Frequently asked questions

What types of skylight are there?

Four families for UK homes: opening roof windows for pitched roofs (VELUX and similar), flat-roof skylights on upstands, roof lanterns (pitched glazed structures over flat roofs), and sun tunnels that pipe daylight into windowless spaces through a reflective tube.

How much does a skylight cost in the UK?

Fully fitted in 2026: pitched-roof windows £900–£2,500, flat-roof skylights £1,000–£3,000, roof lanterns £2,000–£5,000+, sun tunnels £500–£1,200. A small manual roof window starts around £650 installed.

Which is better — a skylight or a roof lantern?

For flat roofs: a flat glass skylight is cheaper, more thermally efficient and flush; a lantern adds height and drama at a premium. For pitched roofs the question doesn't arise — you want a roof window.

Do skylights cause condensation?

Cheap or badly installed ones do. Condensation risk is driven by glazing spec, insulated upstands/collars and room ventilation — specify laminated low-energy or triple glazing in kitchens and bathrooms, and choose an opening unit where moisture is generated.

Keep reading

Are Custom Rooflights Worth the Cost? (2026 UK Prices)

Bespoke rooflights cost £1,000–£4,000+ supplied versus a few hundred for standard sizes. When made-to-measure is worth it — and when it isn't.

Average Skylight Installation Cost in 2026 (UK)

Most UK skylight installations cost £900–£2,500 per window in 2026, fully fitted. Full breakdown: supply, labour, scaffolding, flat roofs and lanterns.

What Is the Best Alternative to VELUX? (2026 UK Guide)

Fakro, Keylite, RoofLITE+, Roto and Dakea compared against VELUX on 2026 prices, guarantees and quality — and which alternative fits which job.