6. Accessory Dwelling Units. During the recession, the McMansions trend gave way to "rightsizing," and with fewer people moving or building because of financial concerns, many are staying put and building accessory dwelling units. These small detached or attached units can be used for offices, studios, in-laws or rentals, and are the ideal size for energy efficiency and green construction.
As rental units, they help cities increase urban density and restrict sprawl, while homeowners add value to their property. The cities of Portland, Oregon, and Santa Cruz, California, waived administrative fees to encourage this.
7. Rethinking Residential HVAC. Advances in applied building science have resulted in homes that are so tightly sealed and insulated that furnace-less, ductless homes can be a reality. The increasingly popular "Passive House" standard, for example, calls for such thick insulation in walls and ceilings that the home is heated by the everyday activity of the occupants, from cooking to computer use.
Even in Energy Star-certified homes, builders are encouraged to bring all ductwork inside the insulated envelope of the house to eliminate excess heat or cooling loss, and to use only small, very efficient furnaces and air conditioners. Geothermal heating and cooling is also gaining broader acceptance.
8. Residential Grey Water. With water shortages looming in many areas including the Southwest and Southern California, grey water recycling of household wastewater is slowly gaining traction. Benefits include reduced water use, less strain on septic and stormwater systems, and groundwater replenishment. Although many cities have been hesitant to legislate grey water use, some communities have increased the amount of allowable grey water for irrigation.
9. Small Building Certification. 95% of commercial building starts in the U.S. are under 50,000 square feet, but most LEED- certified buildings are much larger. This is in part because of numerous "soft" costs including commissioning, energy modeling, project registration, and administrative time, all of which can be prohibitively expensive for small building owners and developers. Certification programs specifically designed for small buildings are springing up, such as Earthcraft Light Commercial and Earth Advantage Commercial.
10. Lifecycle Analysis (LCA). Understanding the lifecyle of building materials - their effect from cradle to grave - has always been important to green builders. Now that we know how various green building materials perform, the industry is studying the effects of these materials over the course of their entire lives, from raw material extraction through disposal and decomposition.
Lifecycle analysts are examining impacts of materials over their lifetime through the lens of environmental indicators including embodied energy, solid waste, air and water pollution, and global warming potential. The results will help architects determine which products really are "green."
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Tom Breunig is Director of Marketing and Communications for the Earth Advantage Institute, a leading nonprofit green building resource and research organization. The group has certified over 11,000 homes, and works with the building and design industry to help implement green building practices.
