Up until the end of the 1980s, nearly all suburban houses in Australia had large backyards by world standards. The older type of suburban form is still characterised by backyards of at least 150m2, and they are commonly several times this figure. They generally have a useful shape and significant coverage of trees. Plot coverages by house footprints are generally 20-30% with a maximum of 35-40%.
However, in the early 1990s, a dramatic change in Australian suburban form began. During this period, the provision of large backyards in new construction ceased and the 35-40% figure now represents the minimum, rather than the maximum, plot coverage. Although some properties may have backyards of 100m2 in area they are normally much smaller than this and are often less than 50m2. Moreover, the narrowness of the gap between the dwelling and the side and rear boundaries of the plot frequently results in this area being in the form of a thin strip rather than a more useful square shape. This change has not been subtle or gradual in either space or time. Two distinct patterns of form are immediately apparent from even a cursory examination of aerial photographs. The older areas are characterised by open yards and tree cover while, in the newer ones dwellings can be nearly roof-to-roof.
All around change
This change is not something that relates to the backyards alone. House and street design have also changed as part of the same process. There has been a trend towards deep, square house plans possessing large internal spaces with little natural light and ventilation. There is also a trend towards fewer and smaller windows. The narrow gap around single-storey houses is dominated by high opaque fences. The frontage is dominated by integral garages.
A common response to this trend is that it must be the result of smaller plot sizes. There is, indeed, a trend to smaller plot sizes in Australia but a closer examination of the data reveals that this not the cause of the phenomenon. The evidence suggests that it is the increase in the dwelling area, rather than the decrease in the plot area, that has been driving the shrinkage of the backyard. There is no evidence that it has been brought about directly by policies of urban consolidation. The phenomenon is to be found at all plot sizes. Most significantly, It is to be found in lower-density outer suburbs located a considerable distance from city centres. Local policies and planning regulations have not explicitly required small backyards. However, there has been nothing in them to prevent the reduction in the size of private open space that has occurred. Requirements for gaps to the sides and rear of properties are generally 1-2m and, where they exist, minimum standards for private open space are tiny compared to the areas of the pre-1990 backyards.
Is this a problem?
Why should this be seen as a problem? The answer is that the shrinkage of the backyard has reduced the amenity of the property in terms of outlook from the dwelling and facilities for outdoor recreation around the home, especially for young children. Moreover, the disadvantages go way beyond the lifestyles of the occupants. The consequent reduction in vegetation, especially tree cover, around the dwelling has led to a loss of biodiversity and an increase in run-off of storm water. The microclimate becomes hotter and this, in turn, requires more air-conditioning and increased energy use. Moreover, it represents a permanent change in built form that cannot be corrected later.
Why then are people choosing to live in such houses? Data on social trends within Australia suggests that the reduction in backyard size has coincided exactly with a trend to substantially longer working hours amongst middle and higher income office workers. At the same time, the growth in the use of air-conditioning has not only allowed, but also encouraged, an indoor lifestyle. For people buying a suburban house, the focus has become one of investment in buildings. A particular house form that maximises floor area at minimum cost has evolved in response. Little priority is now given to planted space around the house, as it is not seen as an investment. The dwelling is therefore extended over as much of the plot as is permitted. These last points remain, for the moment, hypotheses but the questions they raise are ones that cannot be ignored and demand further study and debate.
Professor Tony Hall, Gfiffith Urban Research Program
For more information: The Life and Death of the Australian Backyard, CSIRO Publishing 2010. Professor Hall’s book won the 2012 Planning Institute of Australia Award for Excellence in Cutting Edge Research.