Getting housing density and height right is a creative urban design exercise. There are some general “rules of thumb”, which I will try to cover later, but often what works on one site won’t work on another. What works for private housing may not work for social or assisted housing. What works near a railway station may not work 200 metres away. The right answer is not “rocket science” – it comes from a creative interaction between a community familiar with all options, and skilled architects/urban designers committed to working with that community. In the Sydney region there are good examples of nearly all density/height variations – people need to speak with real knowledge of them.
But, of course, not everybody can be expected to have the knowledge expected of a professional designer, and public tastes and expectations are constantly evolving, as we see more apartments than detached houses being constructed in the Sydney region. I remember my grandmother being quite shocked that her grandson would move back into the dense inner city when her most cherished ambition on getting married was to move to the “suburbs”. The change in housing expectations over two generations has been profound.
Now the Potts Point/Kings Cross area has the highest net density in Australia of around 150 dwellings per hectare, closely followed by the Darlinghurst area. Paddington has half that density. On an international scale Hong Kong and New York have densities of over 1,000 dwellings per hectare. Most commentators agree there is no absolute correlation between density and liveability, but a choice has to be made by individuals – if they have that option. The urbanity of Potts Point comes with reduced open space and increased noise, and the high cost of apartments removes that option from average wage earners. Unfortunately there is no avoiding the reality that land in Sydney is under pressure for increased density in and around the City, resulting from a growing population, a dominant City centre, and the under-provision of public transport infrastructure over the last 40 years.
At the same time we see a growing desire for what has been called an “urban village” lifestyle where residents can retain a sense of place within a pedestrian-oriented, medium-density neighbourhood. These “urban villages” are characterised by reduced car ownership, increased cycle use, pedestrian scale, and enhanced public transport facilities.
In the quest for optimum liveability I believe there are some general guides that can be considered by communities as they come to grips with height and density.
Firstly, maximum liveability seems to be most easily achieved with a mixture of two- to three-storey joined housing, interspersed with medium-density apartment blocks, no higher than six to eight storeys, which appears to be compatible with the desire to retain a sense of human scale and liveability. It has been argued that this scale is directly related to the height of most mature trees. It is possible to go higher towards 12 or even 20 storeys if these blocks are set discreetly behind lower-rise buildings.
Secondly, increased density can be achieved at the same time as a reduction in car usage that allows for a more human-scale environment, without the need for excessive space being consumed for parking and roads.
Thirdly, social groups within developments should be as mixed as possible. The ideal would be a population that exactly mirrored the socio-economic mix of Australian society. I believe it is a valid action of government to promote socially balanced communities in this way.
Fourthly, good design based on sustainability is paramount. Current state guidelines such as BASIX and SEPP 65 can be helpful in this respect. The latter’s use of design review panels of trained professionals is particularly helpful when they provide independent advice on proposals.
Finally, the “urban village” ideas developed by the City of Sydney and focused around walkable village centres, linked by public transport, pedestrian walk-ways and cycle-ways provide a guide to getting housing densities right in inner suburban areas.