About Green Building: Design and Energy Use

A green home is designed to use much less energy than a standard home. Some of this is related to construction techniques -- a tighter seal and better insulation all around prevents heat loss (or heat gain in the summer). With a heat-recovery exchange system you can still get healthy ventilation without losing all the heat from your house. Similarly, using very insulated windows with heat glazing can help keep out the sun when it is hot and keep in or out the heat from leaking through.

But a lot of the energy efficiency comes down managing solar energy as well as possible. In the winter, you want to capture as much sun as possible to heat your home naturally. This means taking advantage of the fact that the sun is higher in the sky in the summer than in the winter. In many locations, a green home will be built with south-facing exposure to capture the sun the winter sun. To prevent the higher summer sun from entering, a green home can have eaves over the windows at the appropriate angle and extent to block most of the sun in the summer. Clerestory windows and light shelves help bring light deeper into rooms to avoid using electric lights (and without transferring all the heat in the summer, too).

Bedrooms can be put on the east side of the building to take advantage of the morning sun (although around here, that needs to be balanced with getting sun too early in the summer). Rooms that you use at the end of the day, for example, the dining room or office, can be put on the western end of the house.

Proper orientation with respect to sunlight is probably one of the biggest advantages for the homeowner -- having the right light in the right room at the right times of day can make a home feel very livable, inviting, and comfortable. Getting the layout right requires more thought than a cookie-cutter plan from a book, but the resulting home will likely have a better layout and be more usable.

Of course, you can also analyze the suitability of your site for wind power and photo-voltaic array. A green home can be pre-wired for solar at a minimal cost (hundreds of dollars added to the total cost of the home). Even if solar power isn't economical now, it may be in 5 or 10 years as prices on PV cells come down; being able to install them and connect them to existing wires will be much cheaper than trying to retrofit the wiring.