Secondary glazing adds a separate glazed layer inside an existing window. It can be worth considering when retaining original external joinery is important.
Why homeowners consider it
Depending on the system, glazing type and installation quality, secondary glazing can help reduce draughts, heat loss and external noise. It does not remedy underlying rotten timber or water penetration.
Appearance and reversibility
For sensitive interiors, frame colour, sightlines, fixings and how the panel opens all matter. Some installations are relatively reversible, but that does not mean every design is acceptable for every listed building.
Permissions and local advice
Listed-building consent may be required for alterations affecting a listed building’s character, including some internal work. Conservation-area controls also vary. Check with the relevant Scottish planning authority before ordering or installing.
Selecting a suitable system
Consider access for cleaning, ventilation, shutters, window operation, condensation risk and fire escape requirements. A measured survey and specification are preferable to choosing on price alone.