Study: Think Small for Green Homes

Oregon DEQ finds less impact, from building materials to energy demand
By Kate Ramsayer / The Bulletin
Published: November 29. 2010 4:00AM PST

When it comes to building an environmentally friendly home, some people offer one simple tip: Think small.

“The greenest thing you can do is build as small as you can,” said Michael Klement, an architect with Architectural Resource, a firm with offices in Ann Arbor, Mich., and Portland. “The whole size component of green is, I think, one of the things that has been woefully overlooked.”

It takes fewer materials and resources to build and maintain smaller homes, he said, and for customers looking to build sustainably, going small can be the cheapest option as well.

A recent study by the Oregon Department of Environmental Quality echoes this. Consultants looked at 30 different ways to reduce building materials and greenhouse gases, said Jordan Palmeri, a waste-prevention specialist with the DEQ, from using Energy Star building standards and special house-framing techniques to constructing a straw-bale home.

But reducing the size of a house — from Oregon's average size of about 2,260 square feet to either 1,600 or 1,150 square feet — had the biggest benefit of all the methods.

“The size of your home is the most influential factor in determining its environmental impacts,” Palmeri said.

Cutting a home's size by 50 percent reduces the greenhouse gas emissions of the home by more than a third, he said. That includes the emissions generated in making building materials, transporting them, constructing the house, heating and powering it, remodeling it and, after 70 years or so, tearing it down.

“When you reduce the size of a house, very simply, you're reducing the energy demand you need,” Palmeri said.

And while that might seem obvious, he said, one of the highlights from the study is that building a home to smaller specifications beat out other options the DEQ considered that home-owners might use to go green.

“It's something that everyone can do. It's not like you need some fancy-schmancy technologies,” he said.

Building an average-size home to Energy Star qualifications, for example, will reduce the greenhouse gas emissions by about 15 percent, according to the study. But shrinking that home by a quarter of the size will reduce it by a couple more percentage points, Palmeri said.

He added that some technologies the DEQ study didn't consider could increase efficiency even more than reducing home size, but the agency just considered the more common green-building practices.

Designing for need

People who are trying to go green when building a home should think about what they need, and then design around that, he said. In the last half-century, he added, home sizes have almost tripled, while family sizes have decreased.

“We're building bigger homes and putting less people in them,” Palmeri said.

For people who aren't thinking about building a new home, they could consider remodeling to add an accessory dwelling unit, often called a mother-in-law apartment. Or get a roommate. Both would decrease the impact of the building on a per-person basis.

Klement, who will be teaching a class on small building through Earth Advantage Institute in Bend on Friday, said that the only thing people have to sacrifice by building small is square footage. The features or feeling of a bigger house can be fit into a smaller area with several tricks, he said, like taking out walls to make spaces seem bigger.

“You can be in one space, but enjoying psychologically the spatial aspects of the space around you,” he said. “The house seems bigger.”

Or designers can play with the skylights and windows, or change the orientation of rooms around a diagonal line, to make a small house seem expansive.

“It's using good principles in design,” he said. “The goal here is to have someone be comfortable with a smaller space and know that all you're giving up is square footage.”

Change in thinking

The thought of saving money on both construction and utilities helps some people adjust to the idea of building small, Klement said. But it will take some changes in the public mind-set to move away from the “bigger and better” association.

“We're heading into an era where we're being challenged to rethink that,” he said.

Bend developer Scott Dahlen thinks that change in thinking is happening now.

“America, in my mind, is kind of coming to its senses,” he said.

He hears from people questioning why they have a room that they only go into to vacuum, or pondering the need for a sitting room off a bedroom.

“Life lives better with the right-sized house, instead of a silly-sized house,” he said.

But builders have to do a better job of meeting demands for smaller houses, he said, and others have to change as well.

Dahlen said he would like to see the city of Bend change the way it calculates system development charges — fees for new construction designed to cover infrastructure costs like sewer lines and roads. Currently, the SDCs for a 1,300-square-foot house are about $18,000 — about the same as for a 5,000-square-foot house.

“I don't believe that's equitable or fair,” he said. “It encourages bigger houses because there's more square footage to spread the cost over.”

But real estate agents also need to stop selling houses based on cost per square foot, Dahlen said. It puts a value just on space, he added, noting that if people sold cars like that, everyone would buy a roomy minivan.

“That's a clumsy way to measure value,” he said.