I just caught up to Jordan Palmeri, author of a study by the Oregon Department of Environmental Quality about the environmental benefits of small homes.
He sent me two great graphics illustrating what he’s learned about the energy efficiency and greenhouse gas emissions associated with houses of varying sizes.
He did an analysis of the greenhouse gas emissions throughout the life of a home – from extracting building materials, to transporting them, constructing a house, living in it, repairing it and demolishing it.
His study found that most of the carbon footprint of a house comes from living in it, and that building smaller can dramatically reduce the emissions associated with heating and electricity.
The graphic above illustrates the difference in carbon emissions if you have a standard home of around 2,262 square feet compared with smaller homes or one that’s larger.
Palmeri has also worked with the Energy Trust of Oregon to find out how much energy you save in homes of various sizes through efficiency measures such as better insulation and low-impact appliances.
Here’s the graphic illustrating those findings:
While energy efficiency measures clearly play an important role, Palmeri said, the savings from building small are significant.
“If you look across the board, a high-performance home at 2,200 square feet is roughly the same as a house built to code at 1,100 square feet,” he said. “This puts efficiency right up against home size in terms of your energy savings.”
I talked with Palmeri at a green home tour earlier this year, and he explained that small homes have a smaller environmental impact right from the start because they use fewer building materials. 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.”