Comfort
An additional internal layer can help reduce draughts and improve the way a room feels.
Outside noise
The glazing specification, seals and space between panes matter. Discuss the noise you experience before choosing a system.
Original character
The existing external window can remain in place, with a separate unit on the room side.
Practical access
Choose an opening style that works with cleaning, ventilation and everyday use.
Security
A second layer can add another barrier. Discuss the locking and glass options that suit your property.
Maintenance & condensation
Discuss ventilation, window condition and access for cleaning. Condensation depends on the property and should not be treated as a guaranteed fix.