Understanding SDG Glazing:

Secondary double glazing is a type of window insulation where an additional pane of glass is installed inside an existing window, rather than replacing the entire window unit. It’s often used in older buildings or in places where replacing the original windows isn’t allowed or feasible (like in listed buildings or conservation areas).

Here’s how it works:

• A second layer of glass is mounted on the inside of the existing window frame.
• This creates an air gap between the original window and the secondary glazing, which acts as an insulating barrier.
• The gap helps to reduce heat loss, minimize noise, and can even improve security.

Key Benefits:

• Cheaper than full double glazing.
• Easier to install — often DIY-friendly.
• Preserves original windows — ideal for historic or period homes.
• Can be temporary or removable if needed.