ENR2 Goes Platinum, Gains Highest LEED Certification
ENR2, the hummingbird haven that captured international attention when it debuted in 2015, is now LEED platinum certified by the U.S. Green Building Council.

By La Monica Everett-Haynes and Melissa Dryden, University Relations – Communications
Sept. 12, 2016

ENR2-0584 South Elevation Looking from SW Corner.jpg

UA alumna May Carr, who served as ENR2's design manager and has since retired from the UA, once said: "Our goal was to create a building that fostered interdisciplinary interaction, with a setup that encouraged people to leave their offices and spend more
UA alumna May Carr, who served as ENR2's design manager and has since retired from the UA, once said: "Our goal was to create a building that fostered interdisciplinary interaction, with a setup that encouraged people to leave their offices and spend more time in open space, connecting with one another. I think we hit a home run." (Photo: Liam Frederick)

The Environment and Natural Resources 2 building at the University of Arizona has achieved LEED platinum certification, the highest possible certification and one of the most distinguished sustainability designations in the country.

In the process, ENR2 simultaneously became the largest project in the state of Arizona, by square footage, to earn the prestigious LEED (Leadership in Energy and Environmental Design) certification under the U.S. Green Building Council's (USGBC) LEED v2009 rating system.

"The University of Arizona ENR2 building's LEED certification demonstrates tremendous green building leadership," said Rick Fedrizzi, CEO and founding chair of USGBC.

"Buildings are a prime example of how human systems integrate with natural systems," Fedrizzi said. "The ENR2 project efficiently uses our natural resources and makes an immediate, positive impact on our planet, which will tremendously benefit future generations to come."

The news that ENR2 is platinum-certified came nearly a year after it was formally dedicated on Sept. 10, 2015.

Globally, LEED platinum buildings and projects represent a unique breed. About 11 percent of all certified projects currently hold the certification, according to USGBC data.

"Under the University of Arizona's leadership we employ innovative and extraordinary sustainable practices which reduce energy use and water consumption while making healthier work spaces that actually improve productivity," said Peter Dourlein, the UA's assistant vice president for Planning, Design and Construction.

"This commitment to efficient and green design and construction saves more than 30 percent in energy and operations cost over typical commercial construction," Dourlein said. "The highly successful team guiding these projects is among the most talented and dedicated people I know, and we all are the beneficiaries." 

The 151,000-square-foot ENR2 joins three other UA buildings with LEED platinum certification: the Student Recreation Center expansion, the Árbol de la Vida Residence Hall and Likins Hall. Also, five other UA buildings have earned either LEED gold or silver.

"I was very pleased, but not surprised, to learn that the UA has once again met the rigorous review requirements to meet the standards for a Platinum LEED certified building, making the ENR2 building the largest in its class in the state," said UA President Ann Weaver Hart.

Building planning began in 2003 and, with Richärd+Bauer Architecture serving as the design architect and Hensel Phelps Construction Co. serving as the contractor, construction was completed during the summer of 2015.

"Because of a dedicated team effort at UA, we continue to be a frontrunner in Arizona in terms of LEED certification," Hart said. "The UA designs and builds structures that help continue great stewardship of our resources, while also providing healthier work spaces and minimizing environmental impact."

Sustainable and Inspirational

For ENR2, which was developed with human and environmental health in mind, "LEED platinum was the goal of the team from the beginning of design and we achieved that," said UA alumnus Henry Johnstone, the principal for GLHN Architects & Engineers, the design professionals for the project.

"Platinum acknowledges that we went the extra mile," said Johnstone, who was chief engineer on ENR2's project team.

Conceptually, ENR2's sustainability features were meant to be functional and inspirational: functional by creating tangible cost-savings for the institution while reducing waste; inspirational in its slot canyon-mimicking design, interactive and shared spaces, and its overall aesthetic, which are meant to evoke collegiality and an appreciation for the natural environment.

As such, many of ENR2's inhabitants actively engage in and promote sustainable practices in both their private and professional lives, whether it be through active recycling, the use of alternative transportation or the investigation of complex environmental challenges worldwide.

The building also has swiftly become an important gathering space for campus and public programming. Given the orientation of its space, it encourages and supports interdisciplinary connectivity among the UA units housed there.

"The LEED platinum certification for ENR2 is great news for those of us who teach or research on the environment because it shows that we try to practice what we preach in terms of workplace sustainability," said Regents' Professor of Geography and Development Diana Liverman, co-director of the UA's Institute of the Environment, one of the units that occupies ENR2.

"The building is not only inspirational but certified environmentally sustainable, and it confirms the flagship role of the building in showing the UA's commitment to sustainability," Liverman said.

Specifically, for LEED platinum, ENR2 gained points for its water efficiency, waste management, use of sustainable materials, indoor environmental quality and innovative design.

Of note, the building has an outdoor air system and induction coils, or active chilled beams — an innovative system that, when combined, works together to heat, cool and ventilate the building. Since it went online last year, ENR2's HVAC system is projected to produce a 32 percent reduction in the building's annual energy budget, as compared with a baseline required for national LEED buildings. ENR2 also contains low-flow faucets and vacancy and temperature sensors that control lights and cooling in individual offices.  

The future-minded building also is efficient in its water usage, resulting in a 40 percent reduction in the amount of water used annually — a reduction of about 640,000 gallons. The water harvesting system, which can be seen in action throughout ENR2 during and after rainstorms, is expected to capture 260,000 gallons of rainwater runoff each year. Rain is an event at ENR2; in August 2016 alone, the building captured 22,000 gallons of rainwater.

Also, no potable water is used for irrigation, which is fed from a 52,000-gallon underground holding and filtration tank located under the building. When harvested water is not available, reclaimed water from a reclaimed water system is offered as a supplement.

"What I’m most proud of, though, is that the building really has achieved actual, tangible energy and water savings in a space that really communicates the idea of sustainable building design," Johnstone said. "It's more than just a building — you can really appreciate and can see what sustainability can be and look like. "

And a beautiful, symbolic thing happened along the way.

Toward the end of construction in the summer of 2015, a female black-chinned hummingbird built a nest on the end of an internet cable and raised two babies, nicknamed "Jack" and "Jill." University Information Technology Services installed a video camera nearby, allowing people around the world to watch the babies grow, thrive and eventually leave the nest. 

Energy Monitoring to Continue

The LEED platinum certification and its various awards do not mark the end of energy optimization in ENR2.

Charlie Lynn, senior mechanical engineer for UA's Planning, Design and Construction, has been monitoring and collecting data on water and energy usage since soon after ENR2 was completed, and will continue monitoring to compile two years of data. Lynn can measure whether the building is operating as efficiently as the design specifications predicted and make adjustments based on the actual day-to-day use of the building. 

Johnstone said he is not aware of this level of post-occupancy improvement being done in Tucson before.

"Having an expert like Lynn monitor the progress and make adjustments along the way allows the University to learn from this experience and evaluate application of these ideas in future building projects," he said.

"The feedback that I have received from those visiting ENR2 who were not involved in the project is that they are encouraged that it is energy efficient, it works and it's cool. This represents the quality of the UA and what can be done in the future."

Extra info

In addition to becoming LEED platinum certified this year, ENR2 also received Contract Magazine's 37th annual Interiors Awards for sustainable interior, the International Interior Design Association's Pride Award, and the Southwest Best Projects 2016 Award of Merit in the higher education/research category.

Fundraisers are underway in support of ENR2:

  • The Institute of the Environment seeks funding to launch ENR2's rooftop garden. Donations will be used to install and maintain the gardens and provide educational signage. To donate, visit the UA Foundation page.
  • Inlays depicting Gila monsters, desert tortoises and hummingbirds are available for adoption. Visit the UA Foundation page for more information. Artists Joe O’Connell and Ty Augsburger of Creative Machines produced the hundreds of metal art inlays of animals, plants and other objects to be adopted.


Resources for the media

Melissa Dryden

UA Planning, Design and Construction



La Monica Everett-Haynes

University Relations – Communications