Here’s some good news for owners of old houses: The January/February issue of Preservation magazine, published by the National Trust for Historic Preservation, offers tips for “greening” your older house while maintaining its historic integrity. Most of these tips are common sense, but the magazine detailed many of the underlying facts and figures to make its case. Though these tips are aimed at residential buildings, many of the principles would also apply to non-residential structures as well.
Richard Moe, President of the National Trust (and a native Minnesotan), was recently awarded the prestigious Vincent Scully Prize, which recognizes exemplary practice, scholarship, or criticism in architecture, landscape architecture, historic preservation, or urban design. In his acceptance speech, Moe offered some insights into the economic and environmental implications of preservation and conservation of old buildings.
Here’s what we have to keep in mind: No matter how much green technology is employed in its design and construction, any new building represents a new impact on the environment. The bottom line is that the greenest building is one that already exists.
It’s often alleged that historic buildings are energy hogs—but in fact, some older buildings are as energy-efficient as many recently-built ones, including new green buildings. Data from the U.S. Energy Information Agency suggests that buildings constructed before 1920 are actually more energy-efficient than buildings built at any time afterwards—except for those built after 2000. Furthermore, in 1999, the General Services Administration (GSA) examined its buildings inventory and found that utility costs for historic buildings were 27 percent less than for more modern buildings.
It’s not hard to figure out why. Many historic buildings have thick, solid walls, resulting in greater thermal mass and reducing the amount of energy needed for heating and cooling. Buildings designed before the widespread use of electricity feature transoms, high ceilings, and large windows for natural light and ventilation, as well as shaded porches and other features to reduce solar gain. Architects and builders paid close attention to siting and landscaping as tools for maximizing sun exposure during the winter months and minimizing it during warmer months.