Building Layouts for Passive Solar

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The ideal layout for a home built around passive solar concepts is a simple rectangle. Not only does this ensure that the long axis of the building gathers as much solar energy as possible (assuming it faces true south, of course), but it also limits the amount of summer heat gathered by the east- and west-facing sides.

If your site suggests a home built on a north-south long axis – to take advantage of a particularly impressive view, for example – you may need to consider alternative layouts. You do not want the long side of the house facing east-west unless you have no other choice, as this massively reduces the amount of solar energy you can gather with your passive solar systems.

When faced with choices like this, remember that the most important factor in passive solar is the amount of wall area facing as close to true south as possible. If you have to build an L-shaped or T-shaped building – or even something more unusual – to achieve a south-facing long axis, it could easily be worth the trouble.

In hot climates, you will also need to consider the east and west faces of the building. Summer heat gain on the end walls can be so great that an active cooling system is needed to keep the home comfortable.

If your region suffers from very hot summers, you may need to obstruct the sun's light on the ends of the building by planting trees, building eaves and awnings, planting arbors or reducing solar gain with judicious use of low-e window glazing or screens that help keep your home cool.