Infill development is needed to accommodate Australia’s expanding urban population sans sprawl, but research from the CRC for Water Sensitive Cities (CRCWSC) indicates that little contemplation has been given its overall effect on water systems.

That which occurs, says director of NMBW Architecture Studio and Monash University Professor Nigel Bertram, is that when permeable vegetation is supplanted with impenetrable humanmade materials like residential structures and pavements, rainwater runoff exerts pressure on stormwater systems.

Traditional infill development, says Professor Bertram, also worsens the urban heat island effect and suburban liveability.

In lieu of a garden, those residing in weakly designed infill developments are looking into a fence. The absence of a canopy can also result in privacy issues, with neighbours able to look straight into people’s houses.

Professor Bertram is a participant in a CRCWCS research project attempting to decipher the possibility of designing infill development which addresses these major obstacles.

Water sensitive infill development is possible, research says.

The team, which includes architects, planners, urban heat and hydrology experts, has conceptualised a range of housing typologies that permit densification without excluding green space.

At its core is the reclamation of additional space on each street for greenery by changing design priorities and making more economical use of space.

Currently, exterior spaces like strips down the sides of homes are thought of as useless. These areas should be tapped for greening potential, particularly if the soil offers sufficient depth to plant a tree.

More efficient use of space is another consideration. Car spots and garages consume much space and are single use. If the resident can park their car along the street, then a garage might become a garden.

Other choices include communal gardens and other common amenities that constitute a more economic use of space. More flexible house designs, in which a single room can hold many functions, also are needed.

The researchers also examined the subject on a precinct scale; one aimed to establish a more symbiotic relationship between the private and public realms.

For example, a treetop canopy on the public street can improve the amenity of homes. A tree canopy overseeing private courtyards at scale could supply quiet cool spots for homeowners.

Bertram also asserts that communities should aim to develop a broad mixture of dwelling types to suit all ages and lifestyles. 

To back up these ideas, which constitute best design practice in many parts of the world, the team is drawing examples and evidence from real life case studies from throughout Australia.

Bertram says that, on a larger scale, builders need to make good, liveable homes at density and scale—for the good of the neighbourhoods, the country, and the world.