Instead of retrofitting the Empire State Building to make it more efficient, what if it was torn down to build a new one? That would be a lot of carbon.



Is It Time To Stop Constructing New Green Buildings?

Sometimes, making a new building is worse for the environment than fixing an old one—no matter how energy-efficient it is.

Step into a new building in certain parts of U.S. and chances are pretty good that it has been built with the environment in mind (and that there is a plaque bragging about it). Maybe there’s natural lighting, a smart HVAC system, or incredible insulation. It doesn’t really matter. No matter what LEED-certified credentials the building can offer, retrofitting the teardown that came before would probably have made more environmental sense.

Preservation Green Lab, a Seattle-based think tank, released a study this week showing that, in the think tank’s words, "the greenest building is the one that’s already built, in almost every case." It’s something that intuitively makes sense, but up until now, the evidence hasn’t been quantified quite to this extent.

The study uses life cycle analysis (a method of measuring impact from cradle to grave) to compare the environmental impacts of reuse and building renovation versus construction over 75 years of use. Preservation Green Lab measured six building types— single-family home, multifamily building, commercial office, urban village mixed-use building, elementary school, and warehouse conversion—across four U.S. cities with varying climates (representative of Portland, Phoenix, Chicago, and Atlanta).

The results are surprising, if not entirely shocking. It can take 80 years for a new "green" building to make up for the climate impact of its construction process with energy efficient features. If Portland reused and retrofitted all the commercial office buildings and single-family homes it plans to tear down over the next decade, the city could save 231,000 metric tons of CO2. That’s 15% of the country’s CO2 reduction targets for the next 10 years.

The report also presents an alarming statistic from The Brookings Institute: one-quarter of today’s buildings in the U.S. are being demolished between 2005 and 2030, creating massive amount of CO2 emissions. But at least some people are getting the hint. According to the U.S. Green Building Council, most buildings across the world that use LEED certification are now retrofits. Up until December 2011, new buildings claimed more LEED certifications.

There are numerous high-profile examples of LEED retrofits, including the Empire State Building (it expects to cut energy use by 38%) and San Francisco’s Transamerica Pyramid, which saves $700,000 each year in energy costs thanks to an onsite co-generation plant. And yet, there’s still something exciting about a new tricked-out LEED building. It’s a novelty that will hopefully fade with time.

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  • Patrice_Frey

    Thanks for the post. I want to clarify one thing related to the subhead that might be misleading to readers: This study did not include evaluation of renewable energy systems such as solar panels or geothermal; our study assessed only the use of energy efficiency improvement strategies, such as HVAC upgrades or added insulation.While our research didn’t examine how the use of renewable technologies would affect environmental impacts over a building lifecycle,  those buildings making use of renewables and achieving extremely high levels of energy efficiency – such as net-zero or living buildings – would potentially provide more immediate benefits than we saw with the energy efficient new construction in our study.  This is an area where more research is needed.
    Patrice FreyDirector of Sustainability
    National Trust for Historic Preservation

  • johnwerneken

    One would have thought that 'reuse' was abundantly obvious. Maybe those of us forced to live in the real world, and re-use many items not only as it may feel 'good' to do so but from necessity,, are just not as smart as the academic types...

  • Brian Hickey


    Does your research find any benefits to building new green construction?  If so, can they outweigh the CO2 emission issue or from an environmental perspective does the emission problem supersede any benefits that a replacement structure could provide?


  • Barry

    The finest green building, designed and constructed to have all the whistles and bells is a complete waste of money if you don't operate correctly. Conversely some of our older buildings, never designed as green can be operated to be high performance...a great example being the Transamerica Pyramid.
    There is a lot to be said now-a-days for dropping out of the LEED NC format and building to LEED Existing Building Standards....after all results are what matters most and operations are the only way to get the best, realtime results that prove that the building is truly high performance.