3-Panel Horizontal Slider Secondary Glazing made to measure for Treflys, Powys. Three horizontally-sliding panels — ideal for wide openings where two panels would be too narrow.
Best for: wide openings and bay windows.
In Treflys, the mix of period and modern housing means owners often want insulation without altering the original frames. Secondary glazing adds a discreet, fully reversible second pane inside the existing frame — cutting heat loss by up to 60% and noise by up to 80%, with no building-regulations approval needed.
Prefer to see the whole range for your area? Visit secondary glazing in Treflys.
Yes — we make horizontal slider · 3 panels to measure for Treflys and across Powys, supply-only or fitted.
It's our recommended unit for wide openings and bay windows.
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.
Configure your exact windows online in about 60 seconds — instant price on standard sizes, fast bespoke quote on the rest. Supply-only or fully fitted.
Start my instant quote →Or call 0800 088 6341 · email sales@secondarywindowsglazing.com