Monday, December 21, 2015

Save The Earth And The Building

Lever House, 1951
Gordon Bunshaft and Natalie de Blois
New York City, New York
Hello Everyone:

Should we try to save iconic buildings that hurt the environment?  This is the question architect James Timberlake addresses in his article for Fast Design titled, "Should We Save Mid-Century Modern Icons That Hurt The Environment?"  This question becomes increasingly important as more and more of our mid-century modern buildings come under consideration for preservation.  This question is also timely, in light of the recently concluded climate talks in Paris, France.  At the summit, world leaders spent a full day discussing"...public policies and financial solutions to reduce carbon emissions within the building sector."  It is a known fact that buildings are responsible for about "30% of global greenhouse gas emissions."  At the same time, there are ongoing discussions, within the construction industry, over what to do about inefficient buildings from previous eras.  The debate is focused on historic value versus economics eventually leading to the big question: "Are these buildings worth retrofitting, or do we tear them down and start over?"

During the post-World War II building boom, approximately 30 million commercial buildings went up, the majority were high-rises that contained work and living spaces in every major city.  The best-known of them were designed by significant architects such as: I.M. Pei, Ludwig Mies Van der Rohe, Philip Johnson, Eero Saarinen, and Edward Larabee Barnes, as well as the firms: Harrison & Abramovitz, Skidmore, Owing Merrill, and HOK.  They were innovative for their time and became part of our collective urban conscious.  Mr. Timberlake gets to the point and asks, "What are the ethics of intervening in these mid-century structures to bring them up to energy code compliance?"

Society Hill Towers
I.M. Pei
Philadelphia, Pennsylvania
Left Behind By Advancing Technology

James Timberlake uses the example of his condominium building-the Society Hill Towers, by I.M. Pei, in Philadelphia, Pennsylvania.  As boy, Mr. Timberlake watched the trio of towers rise up from the ground during a stopover on his way to the 1964 World's Fair in New York.  He writes, "Fifty years later, the residents are debating how to make the buildings energy efficient without destroying their character, which mainly comes from the distinctive egg-crate eco-structure of concrete and the floor-to-ceiling windows."  Mr. Timberlakes cites the windows as the most character defining feature, critical to the building's aesthetic quality.  He continues, "Further, the light, views, and how we inhabit the space all depends on these magnificent views."  Be that as it may, the windows are leaky and provide insulation.  Changing out these windows would require massive renovation within each and every apartment.  The condo board has used best practices to reduce the overall energy costs, upgrading the boiler, replacing the pipes, and installing LED lights.  However, the windows remain the energy inefficient element.  The debate over what to do continues.

United Nations Secretariat Building, 1952
New York City, New York
One of the great things about mid-century design and construction is that it advanced the creation of building envelopes.  Mr. Timberlake writes, "Thin-walled glass construction evolved as an alternative to load-bearing masonry walls with punched windows."  Together with the bonus of expansive views and light came the problem of dealing with solar heat and energy loss through those large panes.  Alan Cunningham observed, in his book Modern Movement Heritage, "how to deal with the design intent of these mid-century curtain wall alongside rapidly advancing facade technology became a conundrum."  If the building cannot be upgraded without changing its character, are these structures preservation worthy?

Century Plaza Hotel, 1966
Minor Yamasaki
Los Angeles, California
Worth Saving? 3 Key Questions

In 2013, sustainability consultants Terrapin Bright Green and strategist Bill Browning published the study, "Midcentury (Un) Modern: An Environmental Analysis of the 1953-1978 Manhattan Office Building."  The report recommended that it was environmentally beneficial to raze these types of building rather retrofitting them with double- or triple paned windows because it would make the building more energy efficient by contemporary standards.  This may seem provocative but it leads to much deeper questions.  Let us start with these three:

1. How much is the facade, or curtain wall to blame for inefficiency?  Currently, it has become quite normal to include embedded environmental impacts in a building's footprint.  Mr. Timberlake writes, "Quantifying the environmental impact of these buildings is essential for environmentally ethical construction and sustainability..."  What is the impact of demolition?  A typical high-rise contains "hundreds of thousands of tons of steel, concrete, glass, and aluminum, much of which may be recycled if properly taken down."  However, when you factor in schedule and cost-if it takes over a year to raze a significantly tall high-rise "...that expense, along with the energy, time and materials already embedded in an existing building may force the argument to re-invest in proper design and engineering, i.e. re-utilizing the existing facade and finding other ways to make the structure energy compliant and efficient."

MetLife Building, 1963
Walter Gropius, Emery Roth, Pietro Belluschi
New York City, New York
2. Does replacing the curtain wall really add up?  More succinctly, "what is the curtain wall value-to-replacement ratio?"  If the curtain wall is retrofitted or replaced, what is the cost in terms of potential energy savings by using a more efficient envelope?  Are the costs mutually beneficial?  James Timberlake tell us, "This is a relatively easy calculation that architects and engineers can do as an act of design."  One example, "life-cycle inventory data sets can be used to account for the upfront environmental cost of materials and the subsequent environmental impact reductions due to operations energy savings."  In short, the more energy saved, the shorter the return period is in context to carbon or costs.

Seagrams Building, 1958
Ludwig Mies Van der Rohe and Philip Johnson
New York City, New York
3. What if you look beyond the curtain wall?  Are there alternative methods for creating energy efficiency other than replacing the curtain wall?  Alternative methods can include energy off-sets and the "essential evaluation of an adaptive reuse of the curtain wall in itself a building system."  Could an additional interior layer be built to mitigate the lack of a thermal break?  Since all sides of a building are not equal, could we consider selective zone replacement on parts of the exterior elevation that gather or transmit the most energy?

The tabla rasa approach would have serious negative environmental and architectural ethics impact.  Mr. Timberlake writes, "We've learned so much over the years about building renovation and intervening in more conventional structures, or more modest versions of these envelopes, how might these lessons be applied to a 30- or 40-story structure or higher?"  How could more active, passive, or hybrid highly energy efficient curtain walls be developed with the help of engineering firms and global curtain wall makers address the issue?

Infrared image of a 27-story high-rise
Currently, architects and engineers have an array of tools that allow them to find a way forward.  One example of a took is thermal imaging, piloted in European cities to discover which buildings are energy inefficient.  Thermal imaging could be very helpful in cities like New York and could guide policies and budget toward betting the environmental performance in regions that require it.  Also, competitions like Construction magazine's 2016 Design Challenge are a way to engage architects and engineers and create an opportunity for dialogue about long-term remedies.  James Timberlake concludes, "The impact of historical architectural infrastructure on the energy crisis is an ethical problem that we can no longer afford to ignore."

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