WHEN it comes to building a new home or renovating an old one, people increasingly want to do all they can to increase energy efficiency.
Cross-ventilation is an important element in passive sustainable design - but what is it and how can it be achieved?
Craig Taylor of Red Blue Architecture and Design said the aim of cross-ventilation was to maximise the amount of natural ventilation in the building.
"In summer, if you can open a house and flush out the warmed air, then you lessen the need to provide artificial cooling," Mr Taylor said.
"The physiological impact of air over the skin is that a cool breeze will cool the body by removing heat from the surface of the body."
So, if natural ventilation can save your need to mechanically lower the temperature, how do you do it?
Mr Taylor said the main windows should be on the house's northern side, which had the additional benefits of improved natural light and winter warmth.
"The windows within the building should be aligned on both sides to promote breeze paths," he said.
"Higher level windows can be provided and be opened at night in summer to allow purging hotter air which rises and gets trapped at the ceiling level.
"As the windows are at a high level, they can be kept open during the evening without a security risk.
Mr Taylor said the most important element in cross-ventilation was to try to keep the building one or two rooms deep.
"If the 'path' that the air has to move through is too complex and is through too many spaces, then the air will stagnate as it finds another way to move from one side of the house to the other, usually by just passing around the outside," he said.
"The great thing about cross-ventilation is that it costs nothing and can be used in any building type."
■ More information: redblue.com.au.