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Lead-framed windows and restoration of old windows

An old craft that is still part of the trade

While modern energy windows fill most of everyday life, part of the profession points far back in history: the lead-glazed windows you find in churches, manor houses and older villas. It is one of the only techniques in the profession where the working method is essentially unchanged for several hundred years.

§What is a lead-lined window?

A lead-came window is assembled from smaller panes of glass held in place by H-shaped lead strips, called cames. The cames are soldered together at the joints, and finally the window is cemented so it becomes stiff enough to stand on its own and tight enough to keep out the weather.

  • 01Glass thicknesses are cut according to a set pattern or cartoon.
  • 02Lead cames are formed and placed around each piece of glass.
  • 03The joints are soldered with a soldering iron.
  • 04The window is glazed to provide stiffness and weather tightness.

§Restoration rather than replacement

On protected and conservation-worthy buildings, the goal is rarely to make the window as energy-efficient as possible at any cost — it is to preserve the building's original appearance. Here, your task as a glazier is to repair what can be repaired and only replace what is actually damaged, so the window's historical character goes along further.

§Old windows and energy improvement

Many old windows can be improved significantly without being completely replaced. A secondary pane or a coupled window can provide much of the insulation that an entirely new pane would — while the original window's appearance is preserved from the outside.

MethodAdvantage
Flyleaf/coupled framePreserves the original window's appearance improves insulation and sound
Complete replacementProvides best possible energy value but often changes the building's appearance

Sometimes the best solution is not the newest – it is the one that respects what is already there.