We carry out condensation diagnosis and fixes in Westminster and across the SW1P area. Condensation forms when warm, humid air meets a cold surface — and a roof lantern is the coldest surface in many kitchens.

What you might be seeing
- Water on the inside of the glass on cold mornings, even without rain
- Drips after cooking, showers or drying clothes
- Wet window sills elsewhere in the house too
Common causes we find
High humidity
Cooking, kettles, showers, drying washing and people all add moisture to the air.
Poor ventilation
Without trickle vents, extraction or an opening vent, moist air has nowhere to go.
Covering Westminster and nearby
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.
Across London, many lanterns sit on rear extensions with access only through the house, so we protect floors and plan the work to keep time indoors to a minimum. Parking and any permits are factored into the quote.
Neighbouring places we cover include Pimlico (1 mile), Chelsea (2 miles), Battersea (2 miles).
What should you expect to pay in Westminster?
Typical range: £145–£495 ex VAT, which is £174–£594 with VAT, per visit. 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?
Most lantern repairs in England need no approval at all. Where a job turns into a replacement, the Building Regulations 2010 apply and we confirm how the work will be signed off before we start. 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.
Condensation diagnosis and fixes in Westminster: questions
How do I get a price for condensation diagnosis and fixes in Westminster?
Send a few photos of the lantern and the problem, with your Westminster postcode. We'll reply with a guide price and tell you whether a visit is needed before we can fix the price.
Can you repair a lantern someone else installed in Westminster?
Yes. We repair lanterns whoever fitted them. If yours is still under the installer's warranty, contact them first so you don't affect it.
What does a condensation visit cost?
Diagnosis visits start from £145 ex VAT. Any fixes are priced separately and confirmed in writing before work starts.
Is condensation in a lantern normal?
Occasional light condensation on very cold mornings can be. Regular dripping isn't, and can damage linings and cause mould.
Other lantern repairs in Westminster
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- Flat roof junction and flashing repairs in Westminster
- Misted glass unit replacement in Westminster
- Opening vent and actuator repairs in Westminster
- Leak investigation and inspection in Westminster
- Commercial roof lantern repairs in Westminster
Condensation diagnosis and fixes near Westminster
More about condensation diagnosis and fixes · All roof lantern repairs in Westminster