Thursday 31 May 2012

Eco Building Design Principles

Over the winter of 2009/10 I started researching (via books and internet) the basic principles behind designing an eco friendly house to go on the site in Crete I had identified in the October of 2009.

There was plenty of inspiration but, in particular, I looked at the earthships of Taos, New Mexico and, more importantly, the principles behind their construction.

In summary, I concluded that my Eco house design:
  • Needs to be not just comfortable to live in but must also remain habitable and safe despite being in an earthquake zone, potentially subject to extensive forest fires in the heat of the summer and, in the longer term, the worst predictions for climate change.
  • Should aim to use the minimum amount of energy to run using passive solar design principles.
  • Use solar hot water and photo voltaic systems to generate on site energy.
  • Maximise the use of on-site spring water and conserved rainwater to minimise use of mains water if connected.
  • Use local building materials and expertise.
  • Use long durability materials to maximise life span of building.
  • Incorporate a large span of south facing windows to maximise passive solar gain.
  • Contain a large thermal mass that sunlight falls upon directly.
  • Minimise east, west and north facing windows.
  • Needs to be well insulated and have low air leakage rates to keep solar heat/coolth within building envelope.
  • Use woodstoves as back-up heaters.
  • Incorporate open floor plans as these best facilitate the thermosiphoning movement of solar heat.
  • Take advantage of the changes in the angle of the sun throughout the year.
  • Use earthsheltering on east, west and north walls and roof to form a cave type dwelling with a living roof that utilises the first 3 metres or so below ground level as a giant thermal mass which remains at a fairly steady temperature throughout the year and is slow to change temperature. In addition this approach makes a low visual impact on the natural surroundings, (which should appease the Archaeology Department of Crete - more in a later post) and use the living roof to stay cool during the long hot summers due to the shading effects of plants, the mass of the earth and the evaporative cooling effect of stored rainwater/watering systems.
Using the above principles I started to formulate a potential house design. 

To be continued!