Heavy-duty four-panel slider for very wide spans with a reinforced frame.
Best for: very wide, high-use openings.
Secondary glazing adds a discreet second pane inside your existing window — cutting noise by up to 80% and heat loss by up to 60% without replacing or altering the original frame. The horizontal slider hd · 4 panels is our recommended unit when you need very wide, high-use openings.
Price depends on size, glass and finish. Our online configurator gives an instant price on standard sizes, or a fast bespoke quote on larger and special units — try it for a figure in about 60 seconds.
Yes. Secondary glazing is internal and fully reversible, so it needs no building-regulations approval and does not affect listed or conservation status.
Both. Choose supply-only, or add installation at £90 per window. Supply-only orders can add an optional site survey for £250.
Configure your exact windows online in 60 seconds, with our launch discount applied automatically. Supply-only or fully fitted — your choice.
Start my instant quote →Or call 0800 088 6341 · email sales@secondarywindowsglazing.com