Traditional stained glass leaded lights are undoubtedly beautiful — and so very Georgian/Victorian England. Leaded glass goes back much further than Victorian times and is common all across Europe, but nowhere embraced it more than England and the Victorians. Well, maybe the Italians but hey.

The English love for stained glass is so evident that you’ll find examples on every Victorian street, from Chelsea to Chorlton. Actually, a lot of what you’ll see in Chorlton isn’t technically stained glass — thanks to me.

I’m asked regularly to look at a Victorian or 1930s front door, and the question always comes up: what can we do about the glass in the door and the surrounding leaded lights?

The problem with existing leaded lights is that they’re often not secure — and they can let air in when the cement between the lead and the glass has become brittle and fallen out. If you take a stained glass unit out to make it safe (using safety glass), you need to sandwich it between two pieces of clear toughened glass. Safe and draught proof. That process is called encapsulation.

Every time Teresa and I looked at a house with stained glass when we were buying, she’d get excited. I, on the other hand, would think: it’s a shame. To take a traditional unit out of its frame, you’d need to make it smaller to fit inside the double glazed unit — and that’s where the compromises start.

I’m not a fan of encapsulation for two reasons. First: you see flat reflective glass from the outside, which destroys any impression that the unit is original. Second: to get the finished unit to fit the existing aperture, you have to cut 25mm off the whole width and height — or make the hole bigger. Neither option is good.

There’s a third problem too. If the glass is for an internal door — where you need safety glass but not double glazing — traditional stained glass can’t be toughened. It’s 3mm hand-made glass. My units can be toughened, because they’re built differently from the start.

I get over all of these issues by making a double glazed unit where the lead work sits on the outside piece of toughened glass. Adhesive lead is applied directly to the outside face of the glass, to a design we develop together. Regalead coloured art film goes on the reverse side — inside the unit — in any sections where colour is required. Lead then goes around those sections to finish the design.

The result is a double glazed unit built with toughened safety glass — the same footprint as the original, no cutting, no bodging — with genuine soldered lead on the outside that you can touch and feel.