Astragal Bars
In double glazing, astragal bars are decorative bars fixed onto the surface of a double-glazed unit to make it look like the window is divided into smaller panes.
What do they do?
Purely decorative – they do not separate the glass
Create a traditional / period appearance (Georgian, Victorian, cottage style)
The glass remains one sealed double-glazed unit
How they’re constructed?
An astragal bar system usually has:
A bar bonded to the outside face of the glass
A matching bar inside the glass cavity (called a spacer bar)
→ this keeps the illusion consistent when you look through the window
Astragal bars vs. other bar types
Astragal bars
Stuck onto the glass
Thicker (often 18–25 mm or more)
More authentic, deeper shadow lines
Georgian bars (internal bars)
Sit inside the sealed unit only
Thinner, flatter appearance
Easier to clean
Pros & cons
Pros
Most authentic “multi-pane” look
Popular for listed buildings or period homes
Cons
Harder to clean (bars on the outside). Can trap dirt around the edges
Slightly more expensive
AJ Windows and Doors can help you decide whether astragal bars or Georgian bars would suit your house better.
