According to recent research by CSIRO, Australian homes are ‘leaky’ by international standards and full of draughts. Australian homes built before the 1950s are particularly problematic. Blocking up draughts is often the most cost-effective way to improve comfort and reduce heating and cooling bills.

Here are some tips to help you address draughts and air leakage in heritage homes.

• Gaps between exposed timber floorboards can be a particularly common problem. Consider underfloor insultation or simply use rugs and carpets to cover the gaps.
• For old exhaust and extraction fans install a ventilation cover to close them when they are not being used.
• Old fireplaces can be blocked with a chimney damper when not in use.
• Consider using honeycomb blinds, thermal blinds or shutters that fit within the window frame. Heavy lined curtains that reach from the floor up to a pelmet above the windows are another alternative.
• Use draught-proof insulation strips and/or caulking around windows and doors.
• If you can feel draughts coming underneath doors, use a brush seal or ‘door snake’ for internal doors, and a plastic or metal door seal for external doors.
• Draughts around the sides and top of doors can be sealed with adhesive weather strips.
• Look for cracks and gaps and around built-in appliances and at the back of kitchen cupboards where pipes or fixtures have been made through the walls. These can be filled with expandable foam filler or air barrier tape.
• Evaporative cooling vents can be covered during winter months with clear plastic vent covers. These easily clip off for summer months.
• Older brick homes can have open vents in the walls and ceiling. Sealing these vents can lead to problems with damp, so proceed carefully. We recommend removable covers to seal these vents, and if you have issues with damp consult with a building specialist before proceeding.
• Do I need a permit? Blocking draughts does not require a planning permit. Use the Three Step guide above to make sure.

Sustainability Victoria has more detailed information on draughts and energy efficiency.

Ceiling insulation is the most cost effective insulation and generally the easiest to install. In Yarra you should aim for at least a  R4.0 rating in ceilings. Make sure your insulation doesn’t touch the metal roof sheets at the edges of the house and be careful to leave space around downlights. Use a reputable installer and refer to the Australian Govt Your Home Guide for more details on insulation.

• Installing ceiling insulation does not usually require a Planning Permit. Use the Three Step guide above to make sure.

Underfloor insulation can be a bit tricky to install, particularly if your house is close to the ground but is excellent at blocking draughts as well as insulating your home. Blocking up the cracks and gaps in old timber floorboards can make a massive difference to your comfort levels in winter. Rugs and carpets on draughty timber floors can also be very effective.

• Installing underfloor insulation does not usually require a Planning Permit. Use the Three Step guide above to make sure.

Wall insulation can be retrofitted, including insulation being pumped into the wall cavities. However, it can be difficult to do comprehensively and can cause moisture problems if not done properly. Speak to an experienced contractor about damp and water ingress and get guarantees from their service and installation.

If you are undertaking major renovations and replacing the weatherboards or plasterboard, then this can be a great opportunity to install wall batts.

• Do I need a permit? Pumping loose fill insulation into wall cavities does not require a planning permit.

Replacing weatherboards can be described as a repair or maintenance so if your building is a “non-contributory” heritage building, or has no heritage status at all, you will not need a planning permit. However, If your building is “contributory” or “individually significant” heritage building a planning permit is required. 

In Victoria the aim of energy efficient windows is largely about keeping as much heat in your house as possible, then stopping it from getting out. The best window specification for achieving this is double-glazed windows.

Double-glazed window units, especially those constructed of timber, are usually of different appearance and character to traditional historic windows which is why they are often considered unacceptable for heritage buildings.

The key deciding factors regarding the introduction of double-glazed windows in a heritage building are:

1. How closely do the new double-glazed windows resemble the original single-glazed windows?
2. Will the new double-glazed windows be visible from the principal street frontage?
3. What is the grading of the heritage building?

There are currently three options for retrofitting double-glazing in a heritage building. See below for more details.

OPTION 1: Installing a secondary glazing system

Secondary glazing is a fully independent window system installed to the internal side of existing windows. The original windows remain unaltered in position so there is effectively no change to the building’s original windows.

Secondary glazing can be designed to be openable, removable or as a fixed unit. The openable panels can be either casements or sliding sashes. These allow access to the external window for cleaning and the opening of both the secondary glazing and external windows for ventilation. There are options for the secondary glazing to be a single pane of glass, or even as a complete double-glazed unit - which will result in three panes of glass in total; the original plus the new double-glazed unit.

Note: Secondary-glazing is usually the only option for improving the efficiency of leaded-light windows.

• Do I need a permit?  NO.  The installation of secondary glazing, if carefully and reversibly carried out, will not affect the significance, character or appearance of the window or the heritage building and therefore would not require a permit for its installation.
  • Suitability: Secondary glazing is acceptable for all windows on buildings of all gradings.
    • Use the Three Step guide above to make sure.
    • See section above for more information on permits in heritage buildings.

Retrofitting double-glazing involves the unobtrusive replacement of the existing single pane of glass with two panes of glass, ensuring that the beads sit in the same place as the existing putty on the heritage window and the installation of a full draining system to minimise rot and help the original frame last.

Do I need a permit?

NO.  The installation of second pane of glazing in the existing window frame, if carefully carried out, will not affect the significance, character or appearance of the window or the heritage building and therefore would not require a permit for its installation.

• Suitability: Secondary glazing is acceptable for all windows on buildings of all gradings.
• Use the Three Step guide above to make sure.
• See section above for more information on permits in heritage buildings. 

The full replacement of existing single-glazed windows in heritage buildings with double-glazed windows should only be considered where the condition of the existing window frames is beyond reasonable repair.

Replacement windows must be constructed of timber and maintain the appearance and dimensions of the various components, such as rails, stiles and glazing bars.

‘Slim-profile’ double-glazing (also known as ‘slimline’ or ‘slim-cavity’) should be used to minimize the gap between the panes of glass and therefore resembles single glazed windows.

Full details of both the existing and proposed double-glazed window frames will be required to ensure that the character and appearance of the heritage building is maintained.

Do I need a permit?

• YES, for all windows on Individually significant buildings, and windows visible from the street on buildings of all other gradings
• NO, for windows NOT VISIBLE from the street on Contributory and Not contributory buildings.
• Use the Three Step guide above to make sure.

See section above for more information on permits in heritage buildings.

External paint controls apply to some heritage overlays. You need to check if these apply to your property.

Where external paint controls apply, replacement windows can be repainted to match the colour of the removed window frames without a permit, however a permit will be required if you want to change the colour. Any new colour will need to be consistent with the architectural period of the main building.

Learn more about heritage paint controls on the Painting a property in a Heritage Overlay page.