No matter the season, leaking windows can pose major problems for buildings including structural and aesthetic damage, increased heating and cooling costs and even health implications where excessive moisture allows the growth of dangerous mould. Window leaks can happen for a number of reasons. It can be the result of improper installation, worn parts or simply poor design.
Leaky windows should not be ignored. If you notice water or a draught coming through closed windows, then you should consider having your windows either repaired or replaced.
When tested in accordance with Australian Standards AS4420.4 and AS4420.5 the best windows on the market will allow no air or water leakage. However, many existing windows in aging buildings fail to perform. There are also many new window types available in the market that meet only the very minimum requirements. This means that they pose a much higher risk of leaking, particularly when installed in certain climate zones and applications where they are exposed to high wind and water pressures.
Poorly designed windows don’t have weather stripping or the barriers necessary to prevent air and water from forcing its way in. Minimising air leakage is particularly important in maintaining a comfortable living environment and reducing energy costs. Australian Standard AS 2047 suggests that window leakage of above 5.0 L/s/m² is considered high. But there are some approved windows that leak the equivalent of a staggering 46 m3/hr/m2 (12.74l/s/m²).
Good quality windows will have a low window leakage of less than 1.0L/s/ m² and should be targeted in order to achieve thermally comfortable and energy efficient buildings in any Australian climate zone.
Whether you are looking for replacement windows or are specifying windows for a new project, be sure to choose windows with exceptional weather resistance features and ask for the performance data as verification.
In addition to this, one of the best and easiest ways to prevent window leakage is to make sure they are installed correctly. By choosing only high quality windows and hiring a certified and experienced window contractor, uncontrolled air and water leaks can be avoided and energy from heating and cooling can be dramatically reduced.