Double glazing that maintains the aesthetic appearance, both inside and outside, is a unique benefit from The Original Box Sash Window Co.

Fully complying with the government's new insulation requirements, Document L, our sealed glass units can be perfectly matched to all character and period windows and doors.

Extremely efficient, completely unobtrusive, the sealed glass looks just like the original. Our units can be confidently used in conjunction with Georgian, Victorian and Edwardian timber glazing bars, which are made by us to match the traditional widths.

To view the product technical specifications, CLICK HERE

What’s the advantage of traditional glazing bars ? To retain the authenticity of the original windows/doors, and disguise the fact that state-of-the-art double-glazing is embedded into the frame. So can you see the windows/doors are double-glazed, with these glazing bars ? Only if you stand up very close to the window and peer into it at a narrow angle to the glass. Otherwise it looks just like a slight shadow round the edge of the glass. Our surveyor can show you a sample CLICK HERE. Are the glazing bars in timber ? Yes. Any other material is characterless when compared with timber. Everything then matches in your new windows/doors: master frame, sash/leaf frames, cills, mouldings, etc to produce that wonderful original effect.

Will the glazing bars last ? We have installed these bars for over 20 years and the timber has not deteriorated at all were normal maintenance has been kept up. What about cleaning ? Clean the windows in the normal way, wiping off the excess water. Nothing more than usual. What about maintaining and re-painting ? The paint we use is micro-porous, i.e. it soaks into the timber and lets it breath. You can go over it as many times as you like without scraping or burning off. Once every seven years to ten years, but inspect yearly. All really easy. Are they secure ? They will never come off. And to break into the window, an intruder would need to smash through the complete window, which is very,very difficult. Will these glazing bars help maintain the value of my house ? Period and character houses hold their prices better than modern ones. In today’s market, keeping up maintenance in a profession way, and re-placing modern features with ones authentic to the original design, is the way to maximise value.

Can you copy the original glazing bars ?

The outside glazing bars are made to look like putty, in fact from a few feet away you wouldn’t know the bars were all timber and not timber/putty.

Inside you can have “lambs tongue” or “ovolo”, which suit different periods of building design. Whichever you choose all the bars and beads match so the final result is a perfect replica.