The old adage, “You can’t teach an old dog new tricks” does not always apply. During a recent national webinar, research staff at the New Buildings Institute (NBI) headquartered in Vancouver, Washington profiled the University of Florida IFAS Leon County Extension building as a case study. This project proves that older office buildings can be successfully renovated to achieve next-generation performance standards, of which the “Holy Grail” is “Zero Net Energy” (ZNE). ZNE buildings are ultra-energy-efficient structures that produce at least as much energy on site as they consume over the course of a year.
With this achievement, the Leon County Board of County Commissioners has joined an elite leadership group of nationally recognized institutions that have implemented energy-efficient technologies and practices in the design, construction or retrofit, and operation of green buildings. The Board’s Extension Center joins a prestigious list of Zero Net Energy buildings. Similar sized recognized buildings include: Oberlin College Lewis Center in Oberlin, OH (built 2000); the Aldo Leopold Legacy Center in Baraboo, WI (2007); and the Leslie Shao-Ming Sun Field Station in Woodside, CA (2002).
There are now 32 “ZNE Verified” buildings nationwide and one “ZNE Verified” district. Two of the ZNE Verified buildings are in Florida, and the one ZNE Verified district is, too; it’s the Anna Maria Historic Green Village. The other ZNE building in Florida is the TD Bank Branch – Ft Lauderdale. Both of these became ZNE Verified during the 2012 operating year, and announced in NBI’s 2013 Research Report.
Average Energy Use Index (EUI) for all 33 ZNE Verified building projects is 21. EUI is NBI’s measure of all energy BTUs (electric and gas) used to power the building. The Leon County Extension building is more energy-efficient than the nationwide average among ZNE Verified buildings, with an EUI of 19. For our square footage, the EUI that most closely matches ours is the Aldo Leopold Center’s. It has an EUI of 16, which is more than offset by its renewable energy generation of EUI 18.
The Leon County Extension building was built in 1961, renovated in 2000, and retrofitted in 2012 – with T8 lighting, solar PV and closed-loop geothermal HVAC (ground-source heat pumps). The energy system upgrades were funded by a federal energy grant and local tax dollars from the Leon County Board of County Commissioners. These upgrades complemented an underground cistern system designed and installed by staff of County Facilities Management and Public Works in 2010-2011. The four-tank, 40,000-gallon, on-site rainwater harvesting and storage system is used for irrigation of demonstration ornamental and vegetable gardens.
Combined, the water and energy conservation system retrofits have transformed the Extension Center into Leon County government’s “Sustainable Building Demonstration,” which was a vision and goal of the Board of County Commissioners and their County Sustainability Coordinator. Their vision enabled a partnership with the building occupants (University of Florida Extension faculty) and citizen advisory committee members to develop the retrofit plans, and to work with Facilities Management to operate the building efficiently.
Our 52-year-old Tallahassee building – plus 7 of the other 32 ZNE Verified projects – were renovations, not new construction. The average (EUI) of the entire renovation group nationwide was not significantly different from that of new buildings constructed with ZNE goals driving the design and engineering process from the ground up, even though new construction gives more opportunity to incorporate the latest technology in the building envelope. NBI hopes that this very important finding provides motivation for a new focus on the opportunity to successfully renovate existing buildings to meet ZNE status, starting with government agencies, academic institutions and corporations.
To learn more visit our office and project information center located at 615 Paul Russell Rd. in Tallahassee, Florida. You may also call the office for details and to arrange a group tour. 850-606-5200.
Visit our real-time eGauge dashboard with calculated energy consumption, production, and savings.