This view shows the solar faces of the test building: southeast & southwest. The two reports contrast the energy balance with the building facing south and with the building turned around to face north. In both cases, the heating fuel is oil. Note the big difference in solar gain. With passive solar design, you can expect 1/3 or more of your heating needs to come from sunlight.

This view shows the northeast and northwest faces of the building. Note that there are considerably fewer windows than the south faces. The two reports compare the operating costs and carbon footprint using propane and wood as heating fuel. You may also compare oil as fuel by viewing the south orientation report to the left.