In Fort William, 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.

Signs you need misted glass unit replacement
- One pane looks hazier than the others
- Misting that comes and goes with the weather
- Water marks or tide lines inside the unit
Common causes we find
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 Fort William
Damp, mild winters keep moss and algae growing on flat roofs and lantern frames, which holds water against seals and blocks weep slots. Regular clearing makes a real difference in wetter areas.
Coastal wind drives rain hard against lanterns, so cappings and ridge seals on the seaward face take the most punishment.
If you're just outside Fort William, we also cover Oban (31 miles).
Guide prices for misted glass unit replacement in Fort William
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 Scotland?
Straightforward repairs — resealing, gaskets, cappings, eaves and like-for-like parts — don't normally need building regulations approval in Scotland. Replacing the whole lantern or enlarging the opening is different and falls under the Building (Scotland) Regulations 2004; we confirm in writing which route 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.
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 Fort William: questions
Do you cover Fort William?
Yes. We cover Fort William, including the PH33 postcode area, as part of Highlands and Islands. 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.
Do you need to visit to price misted glass unit replacement?
Not always. Clear photos are often enough for a guide price. Where the cause isn't obvious, a visit to inspect and water-test is charged from £145 ex VAT, confirmed before we come.
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.
Will the new pane match the others?
We match tint and coatings as closely as possible; a new unit can look very slightly clearer than older neighbours.
Other lantern repairs in Fort William
- Ridge and hip repairs in Fort William
- Flat roof junction and flashing repairs in Fort William
- Cracked lantern glass replacement in Fort William
- Solar control and self-cleaning glass upgrades in Fort William
- Condensation diagnosis and fixes in Fort William
- Leak investigation and inspection in Fort William
Misted glass unit replacement near Fort William
More about misted glass unit replacement · All roof lantern repairs in Fort William