18 Nov Choosing a Sustainable Site
The journey to build an eco-home starts well before deciding on floor plans and materials. While there are ways to design low impact homes on virtually any site, selecting the right site can make a substantial difference to your family’s overall impacts on the environment.
Our homes do not only influence our impacts through the energy and resources consumed on site. There are many other aspects to consider such as the site proximity to work, public transport, schools, shops and amenities. Perth has been found to be Australia’s least sustainable city across 15 different indicators and has one of the highest car dependencies in the world. Average house size in Perth is a whopping 250sqm; well over the Australian average of 215sqm. In Britain the average home is just 76sqm.
An average Australian family’s greenhouse gas emissions can be broken down as shown in the image below. By far the greatest contributor is transport at 34%. It may seem that your choice of house has little to do with your transport emissions. However, this figure can be dramatically reduced by choosing to live somewhere that reduces your family’s reliance on private vehicles; whether this is through proximity to your local school and supermarket, choosing to live walking distance to public transport, or opting to incorporate a home office into your house design to reduce the need to commute.
Home heating and cooling is the next greatest energy consumer influenced by site selection. Of course choosing a site with a northerly aspect makes passive solar design straight forward compared to a site with a southerly or westerly aspect. However there is more to site selection than just orientation: Passive design strategies often rely on breeze paths to purge heat from the summer sun as well as solar access in winter. A tight north facing site that is built up on all sides or sits at the bottom of the valley thereby restricting airflow and solar access is often more difficult to deal with than an open south facing site.
Landscape design can be incorporated into house design to create very cost effective and elegant passive design solutions. However, trees and plants do not grow in days or weeks. Choosing a site with well-located established trees can often provide unique design opportunities which would take years to achieve otherwise.
Other elements to consider when selecting your site include slope (a sloping site can be a design constraint or an opportunity depending on the orientation); noise (passive solar design often relies on opening the house at night to release heat in summer – an unappealing prospect if you are within earshot of a noisy environment), prevailing winds, and local regulations (some sites have very prescriptive design requirements compared to others).
In addition to the environmental factors which influence your site selection, it is important to consider the local community. Will this be a good fit for you and your family? Are there local parks where you can walk your dog? Is there a good school for your children? Are you likely to get on well with your neighbours? Last but most definitely not least – the economics of the site must be considered. If too much of your budget goes into purchasing your site you may end up compromising on the house, and vice versa.
In short, site selection is perhaps the most important decision you will make when embarking on the journey to creating your own sustainable abode. If you feel like you need some help, Custom Green do offer a site selection consultancy service where we can help you to work through the elements described in this article in order to find the ideal site for your home.