Passive Solar Design

Passive solar design is something that was often factored into houses of the past, incorporating design features such as sun-facing orientation (north or south depending on your hemisphere), protective eaves and verandahs.

However lately this seems to have gone out of fashion, with people's use of air-conditioning masking the need for such features and the artificial designs of new housing estate layouts often skewing house placement to suit the block rather than solar orientation. Also, making house prices cheaper by having roofs with no eaves is a very short-term benefit.

The basic passive parameters which I think should be factored into a house design are as follows:

• Eaves - should shade direct solar gain from sun-facing windows during summer
• Orientation - main windows should be sun facing, to allow eaves to protect the interior during summer. Also to benefit from passive solar heating during winter.
• Windows - minimise east and west facing windows to reduce heat load in summer

These are very basic requirements, however looking at many new houses built lately, it is remarkable how little attention is paid to such basics.

However these are also details which cannot be changed in most cases and which can permanently compromise the comfort of the house or require heavy reliance on increasingly expensive power to maintain a comfortable internal environment.