• Credit: Lou Beach

During the mid-20th century, architects often jettisoned masonry construction, passive climate control, daylighting, and traditional building materials in favor of deep floor plans, curtainwall exteriors, HVAC systems, artificial lighting, and new materials. These changes provided unprecedented design freedom, immediate cost savings, and more thorough environmental controls, but they also vastly increased a building’s energy demands, neglected life-cycle costs, incorporated materials prone to obsolescence, and introduced indoor health hazards.

Over the last decade, the General Services Administration (GSA), which owns a vast inventory of midcentury structures and is subject to both federal preservation and sustainability standards, has addressed these concerns. The agency’s work will be the subject of “Managing Modern: Balancing Performance and History in an Era of Sustainability,” a session at May’s AIA National Convention in Washington, D.C. The Saturday-afternoon session will address the GSA’s flexible approach to rehabilitation, with a particular focus on maximizing the capacity of its broad building inventory and gaining the LEED Gold status that is now standard for federal construction.

The ’50s and ’60s also saw a building boom, and today, as the large stock of structures from that boom ages, it is clear that the buildings share particular sustainability and preservation problems. New York’s iconic Seagram Building is a textbook example of midcentury architecture’s preservation challenge, but other structures, such as single-family homes, face similar issues at a smaller scale. Adapting one of these historic structures to new uses prolongs its life and capitalizes on an existing energy investment. This is good news for modern buildings that have flexible and open floor plans (including the Seagram Building or others like it). More-sculptural examples of Modernism that are less adaptable can face abandonment or demolition if their designed purpose changes.

The buildings of the midcentury depend upon a host of innovative technologies, such as exterior cladding systems. Curtainwalls of the period were often constructed of a steel subframe (with glazing and new types of thin panel cladding), which have corroded, proven insufficiently fire-resistant, and frequently lack adequate thermal breaks.

Historic glazing systems are also prone to failure and often less efficient than current panels. Some thin stone, metal, and precast concrete panels have experienced particular patterns of failure, often due to unanticipated interactions between elements within the overall system. Plus, masterpieces of Modern architecture are not always paragons of air quality—a condition exacerbated by all those sealed curtainwalls and aging HVAC systems.

When off-the-shelf parts or systems fail, they are easily replaced. But when proprietary materials or elements are involved, it raises hard questions for historic preservation and restoration. That one-of-a-kind illuminated ceiling system? It survived the first 40 years of service life just fine, but as it systematically begins to fail, it proves impossible to get replacement parts—forcing total replacement of the system, disposal of useful material, and loss of historic fabric.

“The GSA has taken the lead on greening historic buildings—a real commitment. Recognizing that different strategies are appropriate for different kinds of buildings is incredibly thoughtful,” says Jean Carroon, FAIA, principal at Boston’s Goody Clancy and chair of the AIA Historic Resources Committee, which is co-sponsoring the session. “They have a very good system of evaluating the contributing features of each of the buildings in their portfolio, and the GSA is an international model for the stewardship of buildings of all periods.”

To learn more about this and other sessions at the 2012 AIA National Convention, visit convention.aia.org.