Location, location , location… the site for the building can make or break a passive solar design. The ideal site will have good solar access. Preferably a gentle north slope with pleasant views to the north. Look for protection from prevailing winds in winter and from hot afternoon sun in summer. And beware of tantalizing views to the west and/or south as you may be tempted to put too many windows facing the wrong way.
Preferably choose an infill site (like the Greeny Flat site shown on this map) in an already developed area. This helps to reduce sprawl, preserve open space/agricultural land/habitat, maximize use of existing infrastructure, and reduce driving. Because everything we need (including a train station) is within an easy walking distance of the Greeny Flat we could easily live here without a car.
To give an indication of how important this is, the Greeny Flat uses an average of 3.62kWh per day and an average commuter uses about 40kWh worth of energy to drive about 50km per day. In other words, it takes about ten times as much energy to drive 50km/day as it does for us to run our entire house for a day. According to our power bill, the average Australian home with 2 people uses 16kWh/day, so driving 50km/day still takes more than twice as much energy as the average house uses.
As you can see, living close to the things we need and walking or riding a bike whenever possible can have a HUGE impact on our overall energy consumption. Thus the location of our homes is critical for energy conservation.
The site chosen for the Greeny Flat Experiment was the backyard of an existing fibro cottage in Mittagong in the Southern Highlands of NSW. It is a perfect site for a passive solar home with a gentle slope to the north and east and good protection from the south and west.
To the north there is a nice view of Mount Alexandra and the excellent solar access is protected by the street that runs past the house, i.e. there is no neighbour on the north side who could build or plant something that might take away our sunlight. A block to the north is a park with a lake, walking tracks, a kids playground and tennis courts. Beyond that (just far enough so that bushfire is not a likely threat) there is bushland running all the way to Katoomba.
To the east there is good exposure to the morning sun and to cooling easterly breezes in the summer. The solar PV panels are placed on the double garage that sits between the Greeny Flat and the existing house.
To the south there are some taller shrubs and buildings that provide good protection from the cold winter winds. And just three blocks to the south is the main street of Mittagong with ample shops, cafes, pubs, restaurants, a hardware store, etc, etc.
One block to the west is a public primary school and four blocks away is a large shopping centre. The land is a little higher to the west and there are some taller trees which help protect the Greeny Flat from cold winter and hot summer winds.