26 Feb Really Green Homes Begin with Good Design

This past Tuesday, the second session of this year’s Green Boots seminar series at the Austin Home Builders Association events center focused on design. As with many things in life, a good plan can take you a long way. In the case of green building you're specifically planning for efficient use of energy, water and materials in construction and operation. The two primary presenters, both architects, covered a handful of key areas for home design. Much of their information related to seasonal sun and wind considerations, two particular topics stood out for me: maximizing passive cooling and overall impacts of our built environment.

Orientation for Maximum Passive Cooling – Basically what you're doing here is taking advantage of techniques utilized before the advent of central AC. LaVerne Williams of Environment Associates in Houston, threw solar exposure and wind pattern diagrams up on the screen to show how to do effective passive cooling in Central and East Texas. Good passive cooling design involves 1.) Orienting the house with the longer walls facing north/south with deep overhangs on the south side and 2.) placing windows that actually open with smaller openings on the south and larger openings on the north. This minimizes solar heat gain during the many hot months and allows the prevailing south/southeast winds to accelerate through the house. The best place for a kitchen is therefore the north side so heat exits with the wind. And a porch is generally best placed on the south to catch breezes.

Construction & Building Impacts – Francois Levy began his presentation on design-optimized material use by highlighting the massive amounts of resource use associated with our buildings, both commercial and residential (source US Department of Energy). Operation, maintenance and construction of our buildings are responsible for:

• 40% of total energy use (~22% residential)
• 68% of electricity use
• 12% of water use
• 40% of raw material use
• 30% of waste output (~136 million tons/year!)

We've been living in houses for five to ten thousand years, as Mr. Levy pointed out. I definitely agree with him that we still have plenty of room for improvement in the building arena, houses and otherwise.