Building a home from scratch gives you the opportunity to arrange rooms for maximum energy-efficiency and comfort. It also allows you to include money- and energy-saving passive design features that are expensive and difficult to add to existing homes.
Passive design features make the most of the natural features of a site. For instance, they use sunlight to provide natural (and free) heating, breezes for cooling, and vegetation for shade. Here's a quick guide to passive design.
To maximize natural heating, orientate your new house towards south, and build across a wide east–west axis.
Place the most frequently used rooms on the south and install large windows in those rooms to let in plenty of sun.
Less frequently used rooms can be on the north side, and have smaller windows.
Use awnings to provide the appropriate amount of shade. For hot climates in which you want shade year-round, use wide awnings. For cooler climates, design narrow eaves or incorporate moveable awnings to keep the midsummer sun out but let the winter sun in. The optimum width of the eaves will depend on your latitude.
In temperate areas, limit the size of your windows on the east and west sides, and make sure there is plenty of shade, especially on the west side – try using storage areas as a buffer along this side.
Use vegetation to help shade your new house. Deciduous trees provide shade in summer but admit sunlight in winter; evergreens shade year-round. Cultivate grasses and other low-lying plants in front of sun-facing windows to limit reflected heat and glare.
Design your house to make appropriate use of prevailing winds.
In hot climates, design it so that cooling breezes blow through the rooms.
In cool climates, site your house so that it is sheltered from prevailing cold winds, or plant trees and shrubs to block the winds.
Dense materials such as brick and concrete have a high "thermal mass," meaning they will absorb heat by day and redistribute it at night; that makes them better for cooler areas.
Lighter materials have a lower thermal mass, meaning they retain little heat, and are therefore better for hot areas.
If you're planning to build a new house and want to use passive design to help make it more earth-wise, keep this quick guide to passive design in mind.
