Cracked Roof Lantern Glass Replacement

A cracked pane in a roof lantern needs prompt attention because the glass is overhead. We make it safe, measure for a made-to-measure replacement unit, and fit it — normally without disturbing the rest of the lantern.

Two glaziers lifting a replacement glass unit onto a flat roof glazing frame with suction lifters

What are the signs you need cracked lantern glass replacement?

A visible crack in the outer or inner pane
A starburst from an impact point
A crack running from an edge (often thermal stress)
Broken glass inside the room — keep everyone out of the area

What usually causes it?

Impact

Hail, falling branches or dropped tools.

Thermal stress

Uneven heating across a pane, edge damage or partial shading can crack glass from the edge.

Spontaneous breakage

Toughened glass can occasionally break without warning, which is why laminated inner panes are recommended overhead.

How do we fix it?

Make safeWe advise on keeping people clear and, if needed, arrange temporary protection.
MeasureWe measure and confirm the specification, including a laminated inner pane.
FitThe broken unit is removed safely and the new unit fitted, packed and sealed.

Is a cracked roof lantern dangerous?

Treat any cracked overhead glass as a risk until it's been looked at. If the inner pane is cracked, keep people out from under it. If glass has fallen, don't use the room. Send us photos and we'll tell you how urgent it is and whether an urgent make-safe is needed.

What should you expect to pay for cracked lantern glass replacement?

Guide price, per glass unit£295–£795 ex VAT£354–£954 inc VAT · laminated inner pane recommended for overhead glazing

Guide prices assume a standard lantern on a single-storey roof with safe ladder access. Where a tower or scaffold is needed we add it to the quote (typically £245–£895 ex VAT). Diagnostic visits start from £145 ex VAT. Your fixed price is confirmed in writing before any work starts. See all guide prices.

Where is this on the lantern?

Highlighted in amber: sealed glass units.

Do you need permission for this work?

Straightforward repairs don't normally need building regulations approval or planning permission. Replacing a whole lantern, changing its size or working on a listed building is different, and the rules vary by nation:

England

In England, replacing a roof lantern or rooflight is generally treated like replacing a window: the work must meet the Building Regulations (energy efficiency under Approved Document L, and safety glazing), and it's either done by an installer registered with a competent person scheme or notified to building control with an application. Enlarging the opening always needs a building regulations application. Replacing only the sealed glass units in an existing frame is usually treated as a repair rather than notifiable work, but the new glass should be no worse than before — if you're unsure, check with building control. We confirm in writing which route applies before any replacement.

Listed buildings need listed building consent from the local council for alterations, and conservation areas can have extra controls; like-for-like repairs are treated differently from changes, so check with the council's conservation officer first.

Wales

In Wales, building regulations are devolved and the Welsh Government publishes its own Approved Documents. Installing a new rooflight generally needs approval; for a replacement, the Welsh Government suggests using an installer registered with the relevant competent person scheme, or otherwise involving building control, and the new lantern must meet the Welsh energy-efficiency requirements. We confirm in writing which route applies before any replacement.

Listed buildings in Wales need listed building consent from the local planning authority for alterations, with Cadw guidance on historic buildings; check with the council before changing a lantern on a listed property.

Scotland

In Scotland, the Building (Scotland) Regulations 2004 and the Technical Handbooks apply. Under schedule 3, replacing a rooflight including its frame doesn't need a building warrant but must meet the building standards in full; other work to a rooflight, including reglazing, must leave it no worse than before. New or enlarged openings are different and normally need a warrant. We confirm in writing which applies before any replacement.

Listed buildings in Scotland need listed building consent from the planning authority for alterations, with Historic Environment Scotland guidance; check before changing a lantern on a listed property.

Northern Ireland

In Northern Ireland, the Building Regulations (Northern Ireland) 2012 and the Technical Booklets apply, administered by your council's Building Control service. Replacement glazing, including rooflights, must meet the energy-efficiency requirements, and an application may be needed depending on the work. We check with Building Control and confirm in writing which route applies before any replacement.

Listed buildings in Northern Ireland need listed building consent from the council for alterations; check with the council's planning service before changing a lantern on a listed property.

Questions about cracked lantern glass replacement

What does replacing cracked lantern glass cost?

Usually £295–£795 ex VAT per unit depending on size, spec and access, confirmed in writing before work starts.

Is it covered by home insurance?

Accidental damage often is; check your policy. We can provide a written quote and photos for your insurer.

Why did my glass crack on a sunny day?

Thermal stress — one part of the pane heats faster than another, often where it's shaded or chipped at the edge.

Where do we carry out cracked lantern glass replacement?

We cover the whole of the UK. Choose your area for local details and towns we cover.

Cracked roof lantern glass replacement