Misted Double Glazing: Causes, Fixes and Costs

Misted or cloudy double glazing is one of the most common glazing problems in London homes — and one of the most misunderstood. Many homeowners assume they need new frames. In most cases, you just need the glass unit replaced.

What This Guide Covers

• Misting means the sealed unit has failed — not the frame
• Sealed unit replacement cost: £60–£250 per unit depending on size and glass type
• Most frames in good condition can accept a new sealed unit
• Replacement usually takes less than 1 hour per unit
• Much cheaper than full window replacement — save the frame if it is solid

Introduction

London homeowners face unique challenges when it comes to glazing — from period properties with sash windows in conservation areas, to modern developments requiring structural glass installations. Getting the right advice before you commit can save you significant time and money.

At BuilderFix Glazing, we have completed thousands of glazing jobs across Greater London and Surrey — from emergency repairs in Kensington and Chelsea, to bespoke walk-on glass installations in Mayfair and Belgravia. This guide is based on real experience and the questions our customers ask us most often.

What Does This Typically Cost in London?

Costs vary depending on the type and size of work, the glass specification, frame material, and access. As a general guide, always obtain a free written quote before committing — this protects you from unexpected charges.

At BuilderFix Glazing, we provide free, no-obligation written quotes for all work. Our prices are transparent and fixed before we start — no surprises on the invoice.

What to Ask When Getting a Quote

• Is the price fixed, or could it change once work starts?
• What glass specification is included?
• Are all fixings, sealants and finishing included?
• What compliance documentation will I receive?
• What happens if there is an issue after completion?