Older buildings aren't generally known for their energy efficiency. They are often poorly insulated, prone to air leakage, and outfitted with deteriorating windows. It may seem easier and more sustainable to opt for new construction rather than revive an aging structure. But building from the ground up almost always consumes more energy. According to a report by Preservation Green Lab, a department of the National Trust for Historic Preservation, "It is estimated to take somewhere between 10 and 80 years for a new, energy-efficient building to overcome, through more efficient operations, the negative climate-change impacts that were created during the construction process."
On the other hand, inflexible energy codes aimed at new construction can be a deterrent for homeowners or developers seeking to rehabilitate older buildings. In Seattle, the Model Energy Code Project is addressing this very problem. Preservation Green Lab and the city of Seattle, along with the New Buildings Institute, rolled out the pilot program in 2010. It instituted a prenegotiated performance target for owners of existing buildings and gives them the flexibility to achieve energy goals as they see fit. "We intentionally limited the code requirements for retrofits to encourage owners to come up with their own innovative solutions," says Ric Cochrane, Preservation Green Lab's associate director.
The Vance Building in Seattle served as a case study for the Model Energy Code Project. No longer obligated to meet the city's strict codes, consulting firm Arup and developer Rose Smart Growth Investment Fund were able to take a gentler approach, implementing strategies that were geared to the revamping of the 1929 office building's existing features. The design team restored the operable double-hung windows, modified the steam-heating system with thermostatic valves, and replaced the roof with a LEED-approved membrane. As a result of these and other improvements, there has been a 56 percent decrease in energy use for heating. New Seattle Energy Code revisions based on the Vance and other demonstration projects were unanimously approved by the Seattle City Council and made effective in December.
This issue of GreenSource features two projects that illustrate the environmental benefits of salvaging older buildings. In San Francisco, Tom Eliot Fisch and Paulett Taggart Architects renovated the historic Golden Gate Valley Branch Library, reusing original materials while improving energy efficiency and enhancing the interiors with new lighting and improved ventilation. Kohn Pedersen Fox reimagined an uninviting former call center in New Jersey, turning it into a verdant, light-filled headquarters for real estate company Realogy.
Beyond sustainability, restoring a historic structure to its original grandeur, or repurposing an outdated space, is also a great architectural achievement, at once preserving character while meeting today's standards.