Second Chance for Urban Sustainability Strategies
Even the big towns of ancient period such as Athens, Alexandria, Rome, settlements of Incas and Mayan civilisation, were built in accordance with the environmental awareness well known in those times.
Last few centuries, industrial revolution and population growth produced new type of settlements in the hurry which were less and less corresponding with their ecological surroundings. This trend is still ongoing world wide, although contemporary science, architecture and town planning theories make serious efforts to promote sustainable type of housing and dwelling.
“If building green houses is good, then building green housing developments is even better. When you combine sustainable design with densely planned neighbourhoods, you get future-friendly city living. Considering the breakneck speed of urban growth around the world, dense, green housing complexes may be the only way to shelter everyone without compromising the planet.
Green building gets cheaper as builders scale up their developments, one thousand units complex has a marginal cost increase above traditional construction and five thousand unit complex can incur no additional unit cost at all.”[1]
What these numbers are telling us is that united builders will achieve much higher star rating of their homes and fast track their permit process if they work together on volume developments.
Situation in Australia, and particularly in few biggest cities like Melbourne and Sydney is even today extremely critical.
Existing historical heritage of housing in the first circle around the central areas, built on small land parcels more than hundred years ego, with small, one story houses is in the ecological context are very bad example.
Settlements built in the second half of last centuries have somewhat better urban arrangements but unfortunately not well executed in correspondence with today’s well known ecological parameters.
The beginning of our effort is to remind ourselves which ecological parameters are dominant for the creation of new settlements today.
The primary ecological and climate influencers, in order of least applied in Australia, are:
- Geo thermal properties
- Spatial configuration and orientation
- Micro climate and unique wind rose- wind pattern
- Electromagnetism and bio energy
- Seasonal temperature amplitude
- Vegetation, surface water and local bio climate
- Global sprawl building density and proximity
- Building density as direct influencer of mental health and community awareness
- Solar aspects and insolation
In accordance with their effects on the single house or whole settlement, we must adjust our town planning, urban design and architectural knowledge to plan, and build our new developments as ecologically sustainable complexes or organisms, that should perform to much higher standards of living and health.
GEO THERMAL PROPERTIES
Exploration of the potential of geothermal properties can fit in two main categories
a) Active – comprising the installation of geothermal heat pumps. 30 to 100 meters deep syphons providing for stable temperature below ground level to balance temperature changes inside the house.
b) Active – cooling tubes as seen on the Melbourne City Council building
c) Passive – capturing stable temperature below ground level as shallow as 2-3m below ground with thermal mass and vent systems in place not too dissimilar from old fashioned chimney.
Application of the geo thermal properties can be used on single house or at the precinct level.
SPATIAL CONFIGURATION AND ORIENTATION
Best way of addressing spatial configuration and orientation is on the large scale projects where great numbers of houses are grouped. Structure planning and masterplanning of all precincts should incorporate environmentally driven decisions that provide 1, 2 or 3 star improvement for future houses regardless of their other design elements.
Negative southern cooling effect in winter can be overcomed with earth mounds, appropriate design of adjacent buildings or planned building use to best service entire development.
Note that soil mound can act as a quality thermal mass and passive design technique. So if retaining walls are present on site their benefits would best serve the site if they can shelter the house from the south.
Reduced house footprint and increase in strategically placed shared open spaces are crucial in delivering under high environmental principals.