How Much Does a Rooflight or Roof Lantern Cost in Cardiff? (2026 Guide)

If you’re thinking about adding a rooflight or roof lantern to your Cardiff home, one of the first questions you’ll probably ask is: how much will it cost?

The answer depends on the type of rooflight, the size of the unit, the roof it’s being installed into, and whether any additional structural work is required.

This guide covers realistic 2026 costs across Cardiff and South Wales, what affects the final price, and when it may make sense to combine the work with other roofing projects.

Types of Rooflights and Roof Lanterns

There are three main options homeowners typically choose from.

Pitched roof rooflights are installed into sloping roofs and are commonly seen in loft conversions, attic rooms, and upper-floor living spaces. They are often referred to as Velux-style windows and are a popular way to bring natural light into areas that would otherwise feel dark.

Flat roof skylights are fitted into flat roof extensions, rear additions, and kitchen extensions. On older Cardiff terraces and Edwardian semis with rear additions, a flat rooflight is often one of the simplest ways to bring more natural light into a kitchen or living space. 

Roof lanterns are raised glazed structures installed on flat roofs, typically over kitchen extensions, rear extensions, and open-plan living spaces. They are designed to maximise natural light and often become a focal feature within the room. 

Pitched Roof Rooflights – Typical Costs

Type	Estimated Cost (Supply & Install)
Small centre-pivot rooflight	£900 – £1,200
Medium rooflight	£1,200 – £1,500
Large rooflight	£1,500 – £2,000+
Additional unit (same visit)	+£700 – £1,000

These figures are based on standard installations with reasonable access and no significant structural alterations.

Electric or solar-powered opening units typically add between £300 and £800 to the overall cost.

Flat Roof Skylights – Typical Costs

Type	Estimated Cost (Supply & Install)
Standard flat rooflight	£1,000 – £3,000
Kerb / upstand construction	£200 – £500

Costs vary depending on the size of the rooflight, the glazing specification, and whether any additional structural work is required.

If you’re already planning a flat roof extension, installing the rooflight as part of the same project is often more cost-effective than arranging the work separately. Many homeowners choose to add rooflights when upgrading or replacing a flat roof, particularly as part of a kitchen or rear extension project. 

Roof Lanterns – Typical Costs

Type	Estimated Cost (Supply & Install)
Small roof lantern	£2,000 – £3,500
Medium roof lantern	£3,500 – £5,000
Large or bespoke roof lantern	£5,000+

Roof lanterns are usually the highest-cost option, but they also provide the greatest amount of natural light and can become a focal feature within an extension.

The final figure will depend on the size of the lantern, the glazing specification, access requirements, and whether any structural alterations are needed.

What Affects the Price?

What you pay will ultimately come down to a few key factors, including the size of the unit, the type of glazing selected, and the amount of work required to install it. 

The most obvious is size. Larger units require more materials and often involve more structural work.

The type of glazing also makes a difference. Higher-performance glazing can improve insulation and comfort throughout the year, but it generally comes at a higher cost.

Access is another consideration. Properties that require scaffolding or have difficult access arrangements will typically cost more than straightforward installations.

Additional expenses can also include internal plastering, electrical work for opening units, and any structural alterations needed to create the opening safely.

As with any roofing project, the only reliable way to get an accurate figure is through a proper site survey.

Planning Permission in Cardiff

In many cases, rooflights and roof lanterns can be installed under permitted development rules and do not require planning permission.

However, there are some important exceptions.

In conservation areas, including parts of Pontcanna, Llandaff, and Roath, rooflights do not fall under permitted development in Wales, and a planning application will be required before work can proceed.

If you’re unsure whether restrictions apply to your property, it’s worth checking before any work begins. This can usually be discussed during the initial survey stage.

Does It Make Sense to Combine the Work?

In many cases, yes.

If a flat roof is already due for replacement or repair, installing a rooflight at the same time can reduce overall costs by sharing labour, access, and scaffolding requirements.

This is particularly common across Cardiff, where many older rear extensions have ageing flat roofs that are already due for attention.

Combining the work also reduces disruption, as everything can be completed as part of a single project rather than arranging multiple visits.

Thinking About Adding a Rooflight?

Every installation is different, and the final cost depends on factors that are only visible during a proper survey.

Cardiff & Vale Roofing supplies and installs rooflights and roof lanterns across Cardiff and South Wales for both flat and pitched roofs.

Get in touch today to arrange a survey or request a quote, with no obligation to proceed.

We cover Cardiff and surrounding areas including Roath, Canton, Pontcanna, Penarth, Barry, Llandaff, Pontypridd, and across the Vale of Glamorgan.

By Oaks Digital SEO