Well overall, the answer is YES but on average it has only reduced by 67 sqm according to the ABS stats in 2004. But although blocks and houses are getting slightly smaller, the main culprit of the backyard shrinkage come down to one thing. Australians want their house to be a resort and regard their backyard as an entertaining room, an extension of the house. So there is simply no room for the old hills hoist!!
Until the end of the 1980s, nearly all suburban houses in Australia had large backyards often larger than 150sqm, covered with trees and houses generally covering 20â€“30% of the area. Plenty of space for the kids to run around…OUTSIDE!!!
In the early 90s, this began to change dramatically. The McMansion era!! The requirement of large backyards in new developments stopped and the area covered by houses changed from 20 – 30% up to a minimum of 40%+.
If you were to compare aerial photos of newer estates developed past the mid-nineties and estates built pre-1990, you will see a dramatic difference in the green area – ie backyards and area with tree coverage.
So how does this change lead to negative environmental impacts?
Trees and plants around houses have been replaced with large driveways reducing the pleasant microclimates created by these areas.
The narrowness between houses prevents airflow between houses and winds skim over the top of roofs so natural ventilation is at an all-time low. With no natural ways to cool houses down in these new developments, people naturally turn to airconditioning for cooling which in some places is required all year round.
The increase in concreted areas, in turn increases stormwater run-off, which means increased costs for concrete stormwater drains, not just within any development but also for other communities â€˜downstreamâ€™ as they now have to allow for heavy downfalls which would normally be absorbed by the planted areas. All this stormwater runoff could be used could be used to water local plantings which would encourage biodiversity. This is particularly important in the Australian climate, where long dry spells can be punctuated by episodes of heavy rainfall.
In the older suburbs, backyard gardens host a high degree of biodiversity hosting a variety and density of plants. In new development where planted areas have been minimised to a few decorative green spaces, it has serious consequences for biodiversity in general. Another major advantage of the extensive plantings on older suburban lots is that they can absorb or â€˜sequesterâ€™ carbon dioxide and various other pollutants from the atmosphere. Reducing the area of green space and trees within a new development reduces carbon sequestration where it is needed most…in built up areas where car exhausts and other pollutants are at their greatest.
One could argue that the reduction in the Aussie backyard size has led to not only environmental issues but also cultural impacts such as the demise of the backyard cricket match has led to higher divorce rates…but let’s stick to the real fact here.