We Recycle Bottles. Why Don’t We Recycle Buildings?

To confront climate change, we need to make the most of the buildings we already have.

7 min readMar 28, 2019


In New York City, the historic Farley Post Office Building is being transformed into the new Moynihan Train Hall—a critical part of the redevelopment of Penn Station. Image © Empire State Development, courtesy of SOM | Methanoia

By Frank Mahan and Van Kluytenaar

By all appearances, American cities are becoming greener than ever before. Sustainable design has gone mainstream, LEED-certified buildings are commonplace, and redeveloped downtown districts — complete with new bike lanes, buses, and light rail — make a low-carbon lifestyle ever-more attractive. But is all of this really enough to fight climate change?

In the architecture industry and in the media, most of the attention goes to new buildings, often designed to meet high environmental performance standards. At the same time, some of our greenest buildings may be hidden in plain sight: they’re the ones we already have.

A building can only be considered truly sustainable if it remains in use for long enough to justify the resources invested in its creation.

Adaptive reuse — the practice of renovating and adapting existing buildings to serve new and future needs — must become an essential part of any city’s strategy for sustainable urban development. As an alternative to new construction, adaptive reuse has less environmental impact at nearly every level. It bypasses the cost of demolition and construction, all while extending the lifespan of our existing resources.

In many cases, reusing a building is not only the most sustainable development solution, but also the most cost-effective. And with a sensitive design approach, we can renew historic resources to create lasting civic and cultural value.

An alternative to demolition

The crisis of climate change makes it imperative to consider the environmental consequences of demolition. A vast amount of energy goes into a building’s creation, from extracting and processing raw materials required for construction, to hauling and disposing waste from the job site. This is known as the building’s “embodied energy.” Demolishing a building wastes this initial investment. On top of this, add the physical waste of demolition: When a typical…




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