Anatomy of a double-glazed unit
How it works
Built to slow heat, noise & condensation
A double-glazed unit is two panes of glass, sealed around the edge with a spacer bar, and separated by a still layer of air (or an inert gas like argon for higher performance). That sealed cavity is what does the work — it slows heat moving through the glass in both directions, dampens sound transmission, and keeps the inner pane warmer so it resists condensation on cold mornings.
The anatomy
What's in the unit
Four components, working together in a sealed assembly.
Glass
Two panes, commonly 6mm each, selected for thickness and performance grade.
Air Space
A sealed cavity between the panes — the layer that actually slows heat and sound transfer.
Spacer
The bar that holds both panes apart at a precise, consistent gap around the perimeter.
Desiccant
Housed in the spacer, it absorbs residual moisture to keep the cavity clear and fog-free.
Why upgrade
Where double glazing earns its keep
Considering double glazing?
Available across our full window & door range — ask us for a comparison quote.