In Barnet, as everywhere, if a roof lantern pane looks cloudy or wet between the two layers of glass, the sealed unit has failed and moisture has got inside. Send photos and we'll tell you what we think has failed.

What you might be seeing
- Fog, droplets or white bloom between the panes
- Misting that comes and goes with the weather
- Water marks or tide lines inside the unit
Why it happens
Edge seal failure
Every sealed unit has an edge seal and desiccant. Once the seal fails, humid air gets in and the desiccant saturates.
Water sitting on the edge
If the unit's edge sits in water because the eaves don't drain, the seal fails sooner.
Roof lanterns in Barnet
Sun and UV do more damage than rain on many lanterns here: brittle ridge caps, chalky finishes and hardened gaskets. They're cheap to replace before they let water in.
London's extensions are often tight to neighbouring walls and roofs. Where a repair needs access over a neighbour's property, we'll tell you in advance so you can arrange it.
Barnet is around 11 miles from Westminster, and both are within our Greater London coverage.
Neighbouring places we cover include Potters Bar (3 miles), Borehamwood (3 miles), Finchley (3 miles).
Guide prices for misted glass unit replacement in Barnet
Guide price for misted glass unit replacement: £245–£595 ex VAT (£294–£714 inc VAT), per glass unit. Towers or scaffold, where needed, are priced into the quote. Your fixed price is confirmed in writing before any work starts.
Do you need permission in England?
In England, like-for-like repairs to a roof lantern don't usually involve building control. A full replacement or a bigger opening is controlled under the Building Regulations 2010, so we set out the route in writing first. 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.
How does it work?
- Send photosWhatsApp or upload a few photos and tell us when it leaks.
- Guide priceWe reply with a guide price and whether a visit is needed.
- Fixed price in writingYou approve the price and the date before anything starts.
- Repair and testWe fix what's failed, water-test where it matters, and send photos.
Misted glass unit replacement in Barnet: questions
Do you cover Barnet?
Yes. We cover Barnet, including the EN5 postcode area, as part of Greater London. Send photos by WhatsApp or the form for a free guide price, and we'll confirm the fixed price in writing before any work starts.
How do I get a price for misted glass unit replacement in Barnet?
Send a few photos of the lantern and the problem, with your Barnet postcode. We'll reply with a guide price and tell you whether a visit is needed before we can fix the price.
How much does a misted lantern unit cost to replace?
Usually £245–£595 ex VAT per unit depending on size, glass spec and access, confirmed in writing before work starts.
How long does a replacement unit take?
Units are made to measure, so there's a lead time between measuring and fitting. Fitting itself is usually a short visit.
Other lantern repairs in Barnet
- Glazing bar and capping repairs in Barnet
- Eaves beam and gutter repairs in Barnet
- Flat roof junction and flashing repairs in Barnet
- Aluminium roof lantern repairs in Barnet
- Leak investigation and inspection in Barnet
- Commercial roof lantern repairs in Barnet
Misted glass unit replacement near Barnet
More about misted glass unit replacement · All roof lantern repairs in Barnet