ONE OF THE VERY OBVIOUS CHANGES OVER THE LAST TWO DECADES HAS BEEN THE PROPORTION OF THE LOT TAKEN UP BY THE DWELLING.

Analysis of Landgate data shows that since 1993 the size of residential dwellings has grown from 25 percent as a proportion of the lot, to 41 percent.  This is mainly due to the falling lot size (down thirty two percent) rather than the increasing size of the house (up eleven percent).

The increase in small lots has been driven by a range of factors, not least of which being housing affordability, but it does create a number of issues that the industry and government are trying to address.

We have gone through a step change in the types of dwellings being provided compared to the pre-GFC era and there is strong demand for this lifestyle product, particularly when it is close to a park or other amenity.    As with all innovation however, it is not without its technical problems.

Probably one of the trickiest is drainage.  When houses covered only 25 percent of the lot it was easy to manage heavy rain events as the bulk of the rain fell on permeable surfaces such as grass and garden beds.

Today, when you factor in driveways and outdoor paving, up to eighty percent of the site percent of the site may be covered with a hard surface.  This means that the water that falls on the roof and paving must be dealt with either through soak wells or by removing the water from the lot to another holding area.

To make matters more difficult, soakwells are often not permitted within prescribed distances of boundaries.

Small lots also create problems for connecting infrastructure such as power and water to properties.  Developers responded to that problem by providing “rear loaded” lots which have a garage and vehicle access from the back.  This is a great innovation however, the provision of what is effectively two road frontages is not a cheap option.

The industry is continuing to innovate and government agencies are increasingly working cooperatively to find solutions that don’t add cost burdens for the end consumer.  One of the innovations that UDIA is looking for is a “Performance Agreement” approach for infrastructure which focuses on outcomes rather than micro regulatory control of development.  We believe that by setting clear targets, underpinned by agreed standards, we have the best opportunity of achieving both affordable solutions and innovation.