Buildings don't have to be new to be green
Reusing old buildings makes environmental sense, study finds.
Special to The Seattle Times
Riddle: What's the most environmentally friendly way to build a green building?
The answer, according to a recent study published by the National Trust for Historic Preservation, may be not to build at all.
"The notion that you need a blank slate in order to make a green building is incorrect," said Jason McLennan, CEO of Seattle-based Cascadia Green Building Council and one of the partners in the life-cycle analysis study.
The $350,000 study measures the effects of new construction compared with retrofitted buildings in four cities: Portland, Phoenix, Chicago and Atlanta.
It takes into account effects on the environment — for example, whether runoff from a building adds nutrients to a river, causing algae bloom and lower water quality — and whether a project uses nonrenewable resources like fossil fuels.
The report also factors in the amount of additional energy that will be needed to extract resources like metal ores as they become more scarce.
The conclusion was that even the most energy-efficient new buildings have to stand as long as 80 years before their energy savings offset the negative environmental impacts of constructing them.
The report confirms a long-held belief of many in the green building/sustainability field, though it is the first piece of comprehensive research to back up the theory.
"In general, this study finds that building reuse almost always yields better results than new construction," said Patrice Frey, director of sustainability at the National Trust for Historic Preservation.
To carry out the study, the trust partnered with developer Skanska to ensure diversity of perspectives on the research team, Frey said. Skanska is in the midst of designing the new Brooks Sports world headquarters, to be in Fremont.
The building, though new construction, is part of the city's Living Building Pilot Program and is designed with the goal of using 75 percent less energy and water than a typical building its size.
When it came to things like carbon emissions and air and water pollutants, retrofitting proved less environmentally damaging in all instances except when warehouses were converted to multifamily dwellings. The latter had a slightly greater environmental impact compared with new construction, mainly due to the many materials needed for the retrofit, Frey said.
Frey pointed to Portland, which is expected to demolish approximately 1 percent of its residential and commercial buildings during the next 10 years. Were the city to reuse or retrofit those buildings instead, that alone would achieve 15 percent of the Portland's carbon-reduction targets during the next decade, she said.
"From an environmental perspective it's a no-brainer," said Robert Watson, chairman and CEO of green-building consultant and operator EcoTech International.
Watson, who helped develop the Leadership in Energy and Environmental Design ("LEED") green-building certification system, was quick to note that what's good for the environment does not necessarily make good business sense. In most cases, the cost of rehabilitating an old building is nearly equal to building a new one.
"If people are knocking down perfectly good buildings, there's usually an economic reason," he said. "Environmental goals are one thing, but if you're a developer and you can make twice as much money building a building that is twice as big, that's what you're going to do."
Whether it really is cheaper to refurbish or rebuild tends to vary, and depends on the condition of the existing building and how it will be used, said John Leith-Tetrault, president of the National Trust Community Investment Corp.
"We have seen a very wide range of rehab costs project-by-project," he said. "Property developers who specialize in historic rehab consistently tell us that if the envelope of the building is in good condition, the cost of historic rehab is about the same as new construction. So choosing the right building is the key to keeping rehab costs in line."
The study could have an impact on the way developers approach future projects in Seattle.
"There is a lot of potential in buildings that are older and adaptable, and there are great examples of that in Seattle," said Lawrence Kreisman, program director for Historic Seattle.
Kreisman pointed to Pioneer Square's Furuya and Corgiat buildings, built in 1900, as two examples of how renovation rather than new construction helped the environment — and allowed a neighborhood to keep its soul. The buildings were renovated by developer Conover Bond in 2008-09.
There's also the former Cadillac Hotel, which was damaged by the 2001 earthquake, leading to questions about its viability. The hotel's former owners planned to tear it down, but Historic Seattle stepped in with an engineering plan that would preserve the building, and ended up purchasing and refurbishing it.
"Ultimately it's a good project that is fully occupied," Kreisman said.
The stories don't all end that way, but in the future, Watson predicts more developers will at least think about leaving buildings that several years ago would have been demolished standing.
"I think the broader trend from an environmental, as well as a business standpoint, is that we'll probably see more rehab of buildings rather than reconstruction. I don't think it's bad for the developers," Watson said. "Development is about obtaining the maximum return from a piece of property. You don't have to build a new building to make money."
Blythe Lawrence: firstname.lastname@example.org.