I went on a small home tour in Portland last week and met Jordan Palmeri, a Oregon Department of Environmental Quality waste prevention specialist who oversaw this study about the environmental benefits of smaller homes.
On the tour, we met people in Portland who are shrinking their environmental footprints by shrinking the physical footprint of their homes. I saw examples of people building a 160-square foot tiny house on a friend’s driveway, people building a 670-foot retirement home in their own backyard, and people sharing acreage to fit four 530- to 1,600-square-foot homes on one valuable lot.
Small homes have a smaller environmental impact right from the start because they use fewer building materials, Palmeri said. But the benefits keep accruing as the years of less energy use add up. That quickly puts small homes built to code on par with bigger homes that have all the green building bells and whistles.
“People know smaller homes use less materials and energy,” Palmeri said. “The real ‘Aha!’ moment for people was when you compare the benefits of all the other green building practices we incentivize – insulation or PV solar, for example – building smaller is the biggest bang for your buck.”
Palmeri’s report looked at all the impacts of a house from the extraction of raw materials to the deterioration of the waste and quantified the benefits of building small. It found that more than 80 percent of the greenhouse gas emissions over the 70-year life of a home come from occupancy – not construction. So, if you shrink the size of your new home by 50 percent, you can get a 36 percent reduction in total emissions over the life of the house.
Want to save money on green building certifications? Just build smaller, said Palmeri.
“You could achieve the same environmental benefits of a 2,200-square-foot Energy Star Home by building a 1,600 square foot home to code,” he said. “You don’t have to put all the extra money into Energy Star. By simply building less you’re going to get the same benefits.”
Within the last few years, the size of the home has been incorporated into Oregon’s optional green building code (aka Oregon Reach Code).
“Now, if you build a bigger house, it’s required in the Reach Code that that house be more energy efficient to recognize that inherently smaller homes use less energy,” said Palmeri. “It incentivizes smaller homes by requiring more for bigger homes.”
The EarthAdvantage green building certification system has dramatically increased the number of points homeowners get for building smaller. So it’s easier for smaller homes to be certified.
And accessory dwelling units – the small homes people can build on their property in addition to their living quarters – now get the same Energy Trust incentives as a larger home that’s more energy efficient than code requires. ($800 to $3,000, according to this homeowner who did it)
And to top it all off, the City of Portland eliminated the system development charges on building ADUs in 2010 – basically giving homeowners a $10,000 discount on ADU projects.
Palmeri said that sent the number of ADU permit applications soaring from 20 a year before 2010 to more than 100 so far in 2012.