November 13, 2013
Given that most urban buildings will not likely get to net-zero energy consumption any time soon, it begs the question: how do we benchmark energy use as an industry? The industry needs to include a standard measurement for comparing buildings beyond LEED so that tenants and owner/users can compare results to improve building performance. Innovation and improvement typically occur when a standard exists to compare performance of a product, such as the “miles per gallon” metric used in automobiles.
The Urban Land Institute (ULI) is an organization that promotes intelligent urbanization and densification with members of the real estate industry. It focuses on integrating energy, resources and uses to reduce the impact of the built environment and determine the best future use of land. Recently, I was on a ULI panel in Chicago, organized by Mark Kroll of Sares-Regis. It was a Red Flight meeting of the Urban Development and Mixed Use Council (UDMUC).
Our panel addressed cost and payback of green strategies such as LEED and net-zero energy initiatives. I presented several examples of recent DPR “dark green” projects, certified as net-zero by the International Living Future Institute (ILFI). These include DPR’s Phoenix Regional Office, which was the world’s largest ILFI-certified net-zero energy building until October 2013. The “world’s largest ILFI-certified net-zero building” title was then awarded to another DPR project--the 51,000-sq.-ft. Packard Foundation Headquarters in Los Altos, CA.
These net-zero energy buildings generate 100 percent building energy through onsite renewable sources such as photovoltaic (PV) panels. Both the Phoenix office and Packard Foundation Headquarters are low-rise buildings in suburban environments that have space to offset energy use with PV panels.
(Packard Foundation Headquarters photo on left courtesy of Jeremy Bitterman; DPR Phoenix Regional Office photo on right courtesy of Gregg Mastorakos)
In my view, the best metric for comparing buildings is kBtu/sf/yr (also known as EUI--Energy Use Intensity). This metric is calculated by dividing the total energy consumed by a building in one year by the total gross floor area of the building. It is used in calculations of Energy Star ratings developed by the U.S. Environmental Protection Agency (EPA).
I believe the kBtu/sf label should be required for all buildings. You would need to compare similar building types in similar geographies, of course (office buildings in Chicago versus houses in Atlanta versus retail space in Seattle, etc.). This measurement could lead to more direct comparisons of buildings and results. It may also lead to legislation to require minimum energy performance for different building types.
Our industry needs to align around standard metrics for built environment energy use to promote environmental responsibility and spur innovation.