How much does secondary glazing cost in London?

Secondary glazing in London typically costs between £300-£600 per window for professional installation. Factors affecting price include window size, glazing type, and frame material. We offer free surveys and quotes.

Does secondary glazing reduce noise effectively?

Yes, secondary glazing can reduce noise by up to 80% (45dB). It's particularly effective for traffic noise, aircraft noise, and busy urban environments. The air gap between windows is key to acoustic performance.

Can secondary glazing be installed in listed buildings?

Yes, secondary glazing is often the preferred solution for listed buildings as it preserves original windows. It typically doesn't require planning permission as it's a reversible internal alteration.

How long does secondary glazing installation take?

Professional installation typically takes 30-60 minutes per window. Most homes can be fully fitted within a single day with minimal disruption to your daily routine.

Government Grants for Secondary Glazing in 2026: ECO4, GBIS and What Period-Property Owners Can Actually Claim

Government funding for windows is not a universal discount. In 2026, secondary glazing is recognised under relevant energy-efficiency schemes, but eligibility depends on the household, EPC, property and installer route.

ECO4 and the Great British Insulation Scheme

ECO4 and the Great British Insulation Scheme are designed to improve energy efficiency for qualifying households and properties. Secondary glazing is recognised as a measure under these schemes as of 2026, which is important for period homes where replacement windows may not be suitable. Recognition does not mean every owner qualifies or that a grant will cover the full cost.

The fine print

Funding typically targets households receiving means-tested benefits or properties in EPC bands D–G, depending on the scheme and current eligibility rules. Listed-building owners may face additional limits because the measure, property condition and consent position need to be assessed. Do not rely on a cold-call promise: check current information on the official GOV.UK ECO guidance and Great British Insulation Scheme page.

Practical eligibility checklist

Check the current scheme criteria on GOV.UK.
Confirm the property EPC band and address eligibility.
Record benefit or household evidence if the scheme requests it.
For a listed building, gather the listing entry, photographs, window schedule and any conservation guidance.
Ask the installer which measure and delivery route they are proposing before signing.
Get the offer in writing and check whether any contribution, survey or making-good cost remains.

If you are not eligible

Self-funded secondary glazing can still improve comfort and support an energy-efficiency plan. A suitable system can move window performance from U-value 5.0 toward 1.8 W/m²K and reduce heat loss through the window area by up to 64%. For landlords, see our Band C by 2030 guide: the policy is confirmed but not yet in force, the current minimum remains Band E, and the framework includes a £10,000 per-property cap, expenditure from 1 October 2025 and a 10-year cost-cap exemption route.

Compare the real cost

Guide installed prices including VAT are £675 for a small casement, £1,220 for a Victorian sash and £2,565 for a Georgian bay. Use the calculator to understand the starting point, then request a free survey and quote. We will not promise a grant or invent eligibility; the final answer belongs with the scheme administrator and your property assessment.

Frequently asked questions

Can I claim a grant for secondary glazing?

It may be recognised under ECO4 or GBIS, but eligibility and funding are not guaranteed. Check the current official scheme rules.

Do listed buildings qualify?

Some may, but listing status can add consent and technical limits. The property and household must meet the scheme criteria.