Constructing a new, energy-efficient building, even with many green bells and whistles, is more harmful to the environment than reusing an existing structure, according to a report released this year by the National Trust for Historic Preservation.
The group's study, "The Greenest Building: Quantifying the Environmental Value of Building Reuse," concluded that reusing and retrofitting existing buildings almost always offers environmental savings over demolition and new construction.
"When we say something is green and it gets some sort of accolade or LEED certification, in my opinion, what we're really doing is simply smoking Marlboro Lights as opposed to Marlboro reds," said Jeff Myhre of Myhre Group Architects. "We're still smoking. We're still paving. We're still polluting. We're still having an environmental impact on the planet, and that's for any new building, period."
Portland has many aging buildings ripe for adaptive reuse. The trouble is that many retrofits would trigger costly improvements, like seismic upgrades, that can outweigh a building's potential for future revenue.
As of 1996, there were roughly 1,200 unreinforced masonry buildings in Portland that would be particularly vulnerable to collapse if an earthquake were to hit, according to a city survey. Some of those have since been upgraded, but most remain. Some industry experts think more needs to be done to encourage renovations.
"If you (help) owners to get some grants to help them offset some of those costs it would help a lot, because to be honest I feel bad for owners," said Randall Toma of ABHT Structural Engineers. "They all want to do the right thing, but sometimes they're just hamstringed by the costs."
ABHT was the structural engineer for a $20 million project in 2009 that expanded the historic 42,500-square-foot Skidmore Fountain Building into an 80,000-square-foot, Leadership in Energy and Environmental Design platinum-rated headquarters for Mercy Corps. Toma said up to a quarter of the total construction budget went toward seismic upgrades.
But environmental benefits of such projects can also be significant.
The "Greenest Building" study concluded that if Portland were to retrofit and reuse the single-family homes and office buildings likely to be demolished over the next 10 years, it could reduce carbon emissions by approximately 231,000 metric tons - 15 percent of Multnomah County's total reduction target for the next decade.
The report compared environmental impacts of seven types of renovations - such as commercial to office, warehouse to office and warehouse to multifamily - in four cities: Chicago, Atlanta, Phoenix and Portland. It found that 10 to 80 years are needed for a new building 30 percent more efficient than an average-performing existing one to overcome the negative climate change impacts related to construction.
"It took decades before that (new) building became environmentally preferable," said Katie Spataro, research director for the International Living Future Institute and the Cascadia Green Building Council. "So if it didn't last 50 or more years, then it would never see an environmental benefit."
One inherent problem that existing buildings face, Myhre said, is that as their structural value deteriorates over time, the value of the land underneath likely increases. Additionally, if zoning for a mid-rise building allows for high-rise construction, then the existing building is significantly underutilizing its land.
But one question is how scales can be tipped in favor of adaptive reuse. Spataro said the city should perhaps consider a different approach.
"Rather than subsidize building reuse, why not tax or penalize the new construction?" she said. "Right now, in my opinion, we make it too easy to make the new construction happen."
The federal government offers a 20 percent tax credit for rehabilitation of historic income-producing buildings and a 10 percent tax credit for non-historic buildings. The Portland Development Commission offers grants through a storefront improvement program and the city of Portland waives or reduces building permit fees for certain renovations.
Toma said the city of Portland has done a good job of creating triggers in its code book for mandatory seismic improvements. But there are ways around them.
For instance, the code requires that an unreinforced masonry building be seismically upgraded when more than 50 percent of it is re-roofed within a five-year period. Toma said some owners who cannot afford the seismic upgrade will re-roof half of the building, wait five years and then finish the job.
That can create a safety issue as well as an environmental threat.
"If your building fails in an earthquake, you have a lot of debris and materials that are wasted," said Yumei Wang, a geo-technical engineer at the Oregon Department of Geology and Mineral Industries. "Sustainability is more holistic and needs to consider other types of nature's forces. We've embraced solar energy and wind energy, but you can't ignore other types of nature's forces like when the wind blows too hard or the earth shakes."
Toma said one way that incentives could be offered by creating urban renewal areas for life safety upgrades in buildings. Recently, the Historic Preservation League of Oregon held a round-table on the subject; it plans to issue a report in late October.
Alisa Cane, green building and development manager for the city, said the first step toward preservation of Portland's existing buildings is to start a dialogue with the public to identify what it values, because a solution will likely require buy-in.
She said there are numerous adaptive reuse projects that have added to Portland's unique character. In one, a former armory building on Northwest Eleventh Avenue in 2006 was transformed into a theater.
"It's a brick building; it literally has turrets and little windows that theoretically would have guns pointed out of them," Cane said. "It's become sort of a signature building for Portland..... In theory they could have just knocked it down, put up a tower and called it a day. But instead they saw that this is a community asset and it brings so much more vitality to the neighborhood by adapting this old building."