Secondary Glazing Cost vs. Double Glazing: Which Is Better Value?

Secondary glazing is often misunderstood as an inferior compromise. In reality, for many London homes — particularly period properties in Mayfair, Belgravia, Marylebone, Notting Hill, and Kensington — it is the right choice, not a fallback.

What This Guide Covers

• Secondary glazing cost: £200–£600 per window installed
• Double glazing replacement cost: £500–£1,500 per window
• Secondary glazing reduces heat loss by up to 65%
• Noise reduction: up to 54dB — outperforms most double glazing
• Required in many conservation areas and listed buildings where originals must be retained

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?