BU507 Timber windows - retrofit glazing options for thermal improvement

Houses with timber-framed windows and single glazing can have problems with draughts, poor thermal performance and poor solar control. This bulletin contains information on upgrading the thermal performance of existing timber-framed windows in domestic buildings in New Zealand. While concerned mainly with single family dwellings, it is also relevant to flats, apartments and non-residential buildings that use timber exterior joinery.

The bulletin covers:

• existing frames, glazing, materials and performance
• thermal renovation of timber-framed windows
• replacing glass
• secondary glazing
• installng new insulated glazing into existing timber windows
• removal and replacement of windows.