The notorious ex-govie — a common style of brick home that many in Canberra either love or love to hate — can have poor ventilation, aluminium window frames and ineffective exhaust fans.


Condensation in Window

Condensation in Window

Combine that with common winter habits such as drying clothes inside and running humidifiers for croaky kids, and you may as well invite the mould spores to settle in for the season.

Meanwhile many people trying to reduce their heating bill are told to reduce draughts around door and window frames, but it seems the warmer your house is, the more condensation builds on your windows adding to the moisture build-up.

Scientist and energy efficiency experts said there were a few steps you could take to balance energy efficiency and mould prevention.

Draught sealing makes great sense in terms of energy efficiency and keeping you warm when you heat up your air you don’t want it escaping, But you should think of that as separate to the condensation issue.


Install an exhaust fan

Fixing the ventilation and exhausting humid air is the priority, especially for older homes.

A lot of the houses have very old exhaust fans that aren’t ducted outside and they just go into the roof space, so installing an exhaust fan is the first step. Don’t just switch it on while you’re having a shower and then switch it off after you leave, after you shower there’s still a hell of a lot of moisture accumulated in that bathroom so leave the exhaust fan running.


Prevent condensation

Once you have done all you can to reduce moisture inside the home, including putting the laundry racks in a sunny spot outside. It is time to turn your attention to the condensation and keeping the external parts of the house warm.

The condensation occurs because of that build up of moisture and because of cold spots in the building envelope.

The windows are the coldest part in the building envelope so they’re the bit that reaches dew point. The point at which moisture in the air will condense.

You’ll see it on walls as well in colder houses, particularly on those southern areas of the house, the walls themselves will actually reach dew point and get the condensation.

Double glazing hacks

Installing wall insulation is one way to prevent the surface from becoming too cold, and double-glazed windows are also an effective but expensive solution.


There are also products made of perspex that could be attached to the window frame to create a temporary solution.

Be wary of curtains

Heavy drapes are often used as an alternative to double-glazed windows, but while they do reduce heating costs. They could increase your condensation problem.

Once you put a good window dressing in front of a single-glazed window, you’re actually preventing any warm air from reaching that window.

So the window’s going to be even colder than it would have been previously.

If the window dressing isn’t really well sealed, and the moist air can still get around the edges or under the bottom, you’ve made the window colder, so you’ve increased the chances of condensation.

Tackling mould once it grows

For some houses it will not matter what you do, condensation and moisture will still get in and unless you wipe it down daily, chances are mould will grow.