Efficient Urban Planning

While there is considerable scope for increasing the energy efficiency of a home, the greatest benefits come from reducing car use. Whilst efforts to reduce energy consumption in the home may result in other benefits such as noise reduction, the main benefits are simply lower running costs and less pollution. The benefits of reducing car use go much further, and include increasing health and fitness for those who drive less as well as a rather large gain in capital for those who give up actually owning a car. The walking and cycling environment becomes more pleasant and convenient as less people drive (lower traffic speeds helps as well), too. Freeing up land, particularly in inner cities is a major advantage, too. For most of Perth, and indeed, most of our other capitals, getting around without using a car is extremely time consuming, inconvenient and unpleasant in too many areas.

Whatever architects and urban planners can do to get people out of there cars will almost certainly override any benefits better designed homes can offer.

A brilliant paper by Roderick Simpson (one of the initial green architects who helped Sydney get the 'Green' Olympics) for the Ecological Architects Association is GREENHOUSE STRATEGY: SUBURBAN DESIGN vs HOUSE DESIGN.

The relationship between population density can be roughly summarised as low density (ie standard Australian suburbia) being 'good' for cars (plenty of road and parking space) and 'bad' for walking, cycling and public transport. Bad because it is expensive, or inconvenient or impractical.

The huge amount of space required by a car creates congestion when used in higher density areas whereas public transport becomes more cost effective, more passengers per kilometre of route and walking and cycling become far more practical and convenient.

Areas near railway stations and major bus routes (frequent and direct), need to be built up to make the most of the them, to maximise the number of people who can walk there. A theoretical idea of how population density could vary with the distance from a station is given below;

It would appear that this kind of thinking has not been taken up much outside CBDs and even then . . . Unfortunately, too many railway stations are hidden at the back of suburbs and usually between two main roads.

For routes which have buses or lightrail, the stops would be much closer, the picture could look a little like so

How this could actually look at street level is should below;
Good public transport means rail which is direct (doesn't get caught at lights or in traffic), highly visible, constant, frequent and comfortable ie lightrail.

Perhaps the most immediate and obvious step in making our cities more people friendly is to make kerbside lanes bus only on all major roads. This has the additional benefit of promoting the idea of motorists giving up road space to alternative forms of transport, rather than using even more land for transport. The service would need to be very frequent. Traffic light triggers could be placed so that the buses always had green lights. Such lanes would be wide enough to accommodate cyclists, and speed limited to 50 km/hr. Alternatives to paying fares to the driver also need consideration. Councils would need to encourage multistorey and mixed development along the route and discourage parking.

As business, development and passenger numbers grow, so could the frequency of the service, further encouraging local development.

Currently buses carrying 50 people are treated the same as cars carrying one both at the lights and in the use of lanes, the resulting congestion benefits no one.

How dense and where?

As lifts consume small amounts of energy compared to even other forms of public transport, there would appear to be no real limit to increasing population density if energy efficiency alone is the only criteria. However, if it were required that all non-industrial energy use were to be supplied using solar energy alone, the everdecreasing amount of area for collecting solar energy per head of population as the density increases puts an upper limit in the equation.

Increasing density has other benefits apart from reducing the energy required for transport and include

  • reduction in land required
  • reduction in service expenses, ie shorter piping and wiring for telecommunications, electricity, sewerage, water, gas
  • shorter distances to be travelled for postage, recycling and rubbish collection
  • the insulation effect of adjoining building helps maintain internal temperatures

In a paper I wrote for my postgraduate diploma in Science and Technology policy, I came up with a figure of 80 people per hectare (this compares with 14 for typical Australian suburb) for Perth using the technology available at the time.

A look at this kind of thinking taken to its extremes, is shown below.

62k download The idea is that access to the sun for electrical generation and heating is given first priority at the sun's rays. Last year, it was discovered that there now at least two structures using this concept in Germany. Click here for more detail (62k download).
While Singapore and Hong Kong are at one extreme, the ultra low densities of the outer suburbs of our capital cities at are the other.

Impact on Home Energy Efficiency

Higher density housing can offer unique opportunities to get very high ratings. They have an inherent advantage over free standing houses. Shared walls reduce exposure to the outside temperature. In addition, if walls face east or west, they do not get blasted by the summer sun in the early morning or late afternoon.

However, buildings can shade each other from the winter sun and block cooling breezes in the summer evenings.

Careful design can make the most of higher density living.