If you own a period property, you already know the trade-off that comes with original timber sash windows: they're beautiful, they're part of what makes the house what it is, and they leak heat like nothing else in the building. For decades the only real fix was a choice between two bad options — rip out the originals and replace them with uPVC, or live with the draughts and the heating bills.
Fineo vacuum glazing changes that equation.
Standard double glazing works by trapping a layer of gas between two panes. It's effective, but the unit needs to be thick to work, which is exactly why it rarely fits into a slim original sash frame without butchering the joinery.
Vacuum glazing does something different. Instead of gas, the space between the two panes is a vacuum, held apart by a grid of near-invisible micro-spacers. Remove the air, remove the way heat moves through it. The result is insulation performance that rivals triple glazing, in a pane barely thicker than the single glazing it replaces.
That thinness is the whole point for a period property. It means the glazing goes into your existing sash frames rather than requiring new ones.
Not every window is in the same condition, so we work to two paths:
Path 01 — glazing-only retrofit. If your original frames are sound, we retrofit Fineo vacuum glazing directly into them. The frame stays, the sightlines stay, and because nothing structural changes, it typically doesn't trigger planning notification requirements in a conservation area.
Path 02 — bespoke matched replacement. Where a frame has genuinely failed, we build a new bespoke sash window in-house, matched to the original profile, and glaze it with Fineo from the outset.
Either way, from the street, the window looks exactly as it did. From inside, it performs like a modern one.
For the full detail on how both paths work, including U-values, materials and the fitting process, our Fineo vacuum glazing restoration page covers it in full.
We recently completed a full glazing retrofit on a Victorian property in Handbridge, Chester, across both windows and French doors. The whole job was done in just over a week, with no changes to the original joinery's appearance.
That's the case for anyone weighing this up against a full replacement programme: the disruption is a fraction of what you'd face ripping out and rebuilding, and the visual result is what a conservation officer, and a purist, wants to see.
This is squarely aimed at owners of listed buildings and homes in conservation areas, where full replacement is either prohibited or a planning headache, but who are tired of subsidising the local energy company through a Victorian sash frame. It's also a genuine option for anyone who simply doesn't want to lose the character of the originals.
If you've got original windows you love and a heating bill you don't, it's worth a conversation. Visit our Sash and Window Restoration page to see the full service, or contact us on 01244 371571 to talk through whether your windows are a Path 01 or Path 02 job.
