Secondary Glazing Across the UK

Secondary glazing is an additional internal window fitted to your existing window frame. It creates an insulated air cavity between the original window and the secondary pane, dramatically reducing noise and heat loss without replacing the original window. It is the preferred solution for listed buildings, period properties, and any location where preserving the original window matters.

Prices start from around £209 per window for a fixed insert, with most made-to-measure opening units between £600 and £1,300 depending on size, glass and finish. Use our online configurator above to build your window and get a guide price, then a fast bespoke quote.

In most cases, we recommend 4mm for secondary glazing with flexible installation. We recommend 4mm for fixed installation on windows up to 2 metres long, and 5mm for fixed installation on windows between 2-3 metres.

Secondary glazing can reduce noise by up to 80% (54dB Rw) when properly specified. With acoustic laminate glass and a 150-200mm air cavity, it outperforms standard double and triple glazing for sound insulation.

Yes — secondary glazing is the preferred solution for listed buildings and conservation areas. Because it is fitted internally and does not alter the external appearance, planning consent is rarely required. Suitable for Grade I and Grade II listed properties.

Yes. Secondary glazing can reduce heat loss by up to 60% and improve room temperature by up to 4°C. Energy efficiency savings of up to 60% are achievable, with annual heating cost reductions of £200-£400 typical for an average UK home.

Yes — in most cases, installing secondary glazing will eliminate condensation entirely. It works by reducing the temperature difference between inside and outside surfaces, particularly effective in older properties with single-glazed windows.

Secondary glazing adds an additional internal window to existing frames, while double glazing replaces windows entirely. Secondary glazing is far better for noise reduction (up to 80% vs 40%), cheaper (£300+ vs £500+), suitable for listed buildings, and preserves original windows.

Installation typically takes 1-2 days depending on the number of windows. From order to installation, the typical timeline is 2-4 weeks, with manufacturing taking the majority of that time.

Yes — Secondary Windows Glazing operates nationwide across England, Scotland, Wales and Northern Ireland. Our installation teams cover all counties and major cities from London to Edinburgh, Cardiff to Belfast.