Balancing Historic Preservation and Sustainability in Federal Buildings
An Interview with Eleni Reed, Chief Greening Officer, Public Buildings Service, U.S. General Services Administration
The next installment in the For the Greener Good series (March 24, 2011 at 6:30 p.m.) features a panel discussion on the issue of “Historic Preservation vs. Sustainability.” In advance of that program, National Building Museum Online talked to panelist Eleni Reed, the U.S. General Service Administration’s chief greening officer, about what can be learned about energy efficiency from historic buildings.
National Building Museum Online: What
can we re-learn about energy efficiency from historic buildings?
Eleni Reed: Our monumental public buildings from the nineteenth and early twentieth centuries were built to last, with durable materials and high-quality craftsmanship—offering many sustainable advantages, as they were designed and built with passive and other operable features to manage natural daylight and air circulation, heating, and cooling. As we invest for extended life with high expectations for improved energy and work performance, General Service Administration (GSA) reinforces these energy-efficient and common sense attributes while recognizing that new technologies can enhance and complement passive sustainability.
With new federal mandates requiring reduction of greenhouse gas emissions and a goal towards zero fossil fuel-generated energy consumption, GSA has set forth a global imperative: to be a proving ground for innovation in sustainability. Recent modernizations of our historic buildings have allowed us the opportunity to correct well-intentioned, but often deleterious, past renovations, which were insensitive to the inherent sustainable features of buildings—cutting off natural daylight and ventilation, removing shading devices and trees, and obliterating original finishes with less-durable, sometimes toxic, finishes. Ongoing efforts seek to recapture many inherently green features that were original to buildings related to light, ventilation, materials, shading, and landscaping as we are able to incorporate new technologies, when necessary, to enhance energy, life-cycle, and building performance.
National Building Museum Online: How does the GSA calculate a building’s embodied energy? How might this information influence future federal construction and renovation projects?
Reed: GSA is focused on pending and future impacts rather than looking back at energy spent in the past. As stewards for the federal government we value our existing buildings and always look first to the reuse of existing federal buildings to meet current needs. We seek to develop innovative design solutions that are affordable, extend the useful life of existing buildings, and minimize the negative effects of changes needed to keep them safe, functional, and efficient. The use of life-cycle costing helps to focus investment decisions on the value of long-term system improvements, especially within the context of long-term assets such as historic buildings. Federal life-cycle cost analysis had traditionally been based on a 25-year system life, but has recently been increased to a 40-year life cycle, further supporting the value of long-term system investments. In addition, building energy audits and studies for net-zero buildings are currently underway that will also inform future work.
National Building Museum Online: Many mid-century modern buildings were constructed using experimental materials in the 1950s and ’60s. What are some of the challenges to making these buildings energy efficient while respecting their original design?
Reed: Mid-century modern buildings constitute one-third of GSA’s inventory. We face formidable performance problems in buildings not designed to last 100 years—buildings conceived and constructed quickly to accommodate a rapidly expanding workforce. GSA holds many mid-century masterpieces in its collection, many of which have been listed in the National Register of Historic Places; scores of others, far less than exceptionally significant, but strong performers in the portfolio, are approaching the 50-year federal threshold for evaluation. The primary challenge lies in balancing their potential significance with deteriorated or toxic materials, failing and inefficient systems, and an urgent need for intervention. GSA has and continues to take a federal leadership role in the approach to these properties and in creatively balancing, where possible and necessary, original design intent and expression, with improved performance. In all cases, we will look first to capitalize, wherever possible, on existing structure, materials and systems; maintain form and proportion; all while introducing cutting-edge technology and workspace design to provide healthier, more efficient buildings for federal agencies and the communities in which they are situated.
National Building Museum Online: GSA has found that buildings constructed before 1930 have the most cost-effective energy retrofits. Why is this so?
Reed: A 1999 GSA study on operating costs found that GSA historic buildings used less energy than our non-historic buildings. Public buildings constructed before World War II generally have thicker walls and fewer, smaller windows recessed with inherent shading than buildings constructed after the war. This construction resulted in greater thermal mass, naturally insulating the buildings. Also, most historic buildings have generous natural daylight that, coupled with the addition of smart lighting technologies, reduces the demand for electricity during the day. GSA is using daylight sensors, individually-controlled task lighting, and smart lighting system controls to make the most of the generous daylight many historic buildings offer.
National Building Museum Online: During a retrofit, how does GSA assess a building’s historic significance?
Reed: For all buildings listed in or eligible for the National Register of Historic Places, GSA prepares Building Preservation Plans (BPPs) to document the buildings’ significance and their historic spaces and character-defining features. Each BPP includes preservation zones delineating a hierarchy of spaces from most to least important to provide guidance on which spaces and materials are significant and merit restoration or sensitive rehabilitation. Beyond the major public spaces such as the lobby, major corridors, courtrooms, libraries, executive offices, and other significant areas, many of the secondary and tertiary spaces contain few significant materials, allowing for flexibility to meet the functionality of a modern office building, including energy and building performance goals. Our design teams include well-qualified preservation architects skilled at rehabilitating historic buildings while incorporating modern technologies to accommodate contemporary use.
National Building Museum Online: How do GSA’s green building initiatives relate to the agency’s historic preservation goals?
Reed: GSA’s approach to sustainability is a logical, natural extension of our Federal historic building legacy, long-established stewardship strategies, and commitment to advancing innovative building practices that promote longevity while conserving finite resources. GSA policy advocating consideration of historic buildings and sustainable (i.e., walkable/transit-oriented) locations dates to the 1966 National Historic Preservation Act and subsequent Executive Orders. It calls for the use of available historic buildings, reinvestment in central business districts, and the promotion of historic buildings in city center historic districts and town centers. This philosophy of reinvestment is known as our historic building "Legacy Vision."
