This week’s business media coverage in New York City manipulates a recent report by the consulting firm Terrapin Bright Green, by suggesting that the best way to improve the energy efficiency of Midtown Manhattan’s mid-century office towers is to raze them and build anew. This is a gross oversimplification of the report’s key findings, driven in part by commercial developers interested in upzoning this high value neighborhood.
The truth is, of course, more subtle: One size does not fit all.
As a peer reviewer of Terrapin’s report, entitled “Midcentury (Un)modern,” I understand firsthand the breadth of its actual findings which include the following: Older buildings, if well maintained, can achieve better than average energy efficiency.
However, the report’s blanket assertion that demolition and new construction are environmentally preferable for an entire class of buildings is overly simplistic and troublesome. In reviewing the report, the Preservation Green lab explained that "we would be concerned if the report was used to justify the indiscriminate tearing down of mid-century buildings without some level of additional analysis that is particular to the building in terms of its retrofit potential.”
It seems our fears were well founded.
The Preservation Green Lab understands the complexities and nuance of this debate better than most. We released our own comprehensive study on the environmental value of building reuse in 2012. And we are grateful for any chance to advance the conversation about making commercial buildings more energy efficient.
Terrapin’s latest contribution to this discourse tackles the specific question of whether it is possible to retrofit typical mid-century buildings in a cost-effective manner. These buildings are often some of the poorest performing in our nation’s building stock, and most are long overdue for efficiency improvements.
In considering these issues, however, it’s important to keep a few realities in mind:
All buildings are not created equal. Terrapin’s report assessed one building in great detail, the 47-year-old Durst Building at 675 3rd Avenue, and concluded that retrofitting this structure would be costly and technically difficult to achieve. While this analysis may be methodologically sound, the potential energy savings within every building—even those constructed in the same era—varies significantly and relies on many assumptions. As such, it is misleading to suggest that just because one structure is not cost-effective to retrofit, others of that same vintage won't be either. We shared this concern with Terrapin during our review of its draft report, noting that each individual building needs to be considered on its merits.
Time is not on our side. It is wrong to infer, as some news reporters have done, that Terrapin’s research justifies the demolition of buildings based on environmental terms. The report finds that it will take 15 to 28 years for new, taller buildings to recover the environmental impact (read: greenhouse gas emissions) expended during the construction process. Unfortunately, we don't have 15 to 28 years to reduce our emissions—the clock has long been ticking. It is also worth noting that Terrapin's conclusions are consistent with the Preservation Green Lab's key finding from the Greenest Building report that it takes, on average, 20-30 years for a new building to "recover" from the impacts of construction through more efficient operations. Will some buildings need to be demolished to accommodate needs related to population growth and density? Of course. But these calculations are complex, site specific, and must weigh the impacts of a given demolition with a city’s larger, long-term needs.
Landmarks deserve unique consideration. Terrapin is a firm that has done great preservation work and has demonstrated its commitment to historic preservation. Terrapin’s study actually makes it quite clear that landmarked buildings deserve separate consideration, based on their historic and cultural significance and not just their energy performance. This is a point where Terrapin and the Green Lab agree wholeheartedly. And Terrapin would do well to clarify that it doesn't support the wholesale demolition of landmarked buildings.
The body of available research on the environmental value of building reuse is growing by leaps and bounds. The Preservation Green Lab is honored to play an active role in this important civic dialogue, and we welcome the open exchange of ideas on all sides. What’s critical, however, is that all who engage in this conversation—including the news media—understand the complexities involved. One size fits all solutions are rarely that simple, or useful.
Author's Update 4/29/13, 4:30pm: The Atlantic Cities has just posted an article featuring the Terrapin report that captures the complexities of this debate. Read that story here.