Only two facilities in Illinois have achieved net-zero verification by the New Buildings Institute, and the Park District of Oak Park can lay claim to one. The Carroll Center, which was built almost a century ago, officially snagged the sustainable standing Feb. 1.
Carroll Center is at 1125 S. Kenilworth Ave, adjacent to Lincoln School.
NBI is a non-profit organization that seeks to improve the energy efficiency of commercial buildings across North America. An addition to Adlai Stevenson High School in Lincolnshire became the state’s first NBI-verified net-zero building last year. Yet, the Carroll Center’s status as the state’s second NBI-verified net-zero structure is still very prestigious; a mere 148 buildings in North America have achieved net-zero verification from NBI.
To be net-zero, a building must generate as much energy as it uses. To prove that the Carroll Center’s energy use equals the energy it produces, the park district submitted a year’s worth of energy data to NBI at the end of January.
“We were really vigilant in our process,” Chris Lindgren, the park district’s superintendent of parks and planning, told Wednesday Journal.
The park district used special metering software to monitor the building’s energy usage. That data was compiled into daily, weekly and monthly reports, which helped identify potential energy leakages.
“There’s actually equipment that gives us the exact real-time data of all the energy usage in the building,” said Lindgren.
Staff were also trained to treat energy use differently to ensure the building met the qualifying standards. The preschool teachers that hold classes in the Carrol Center received training too.
“People that operate [net-zero buildings] and work in them need to know that energy needs to be used differently,” said Lindgren. “It’s not just an unlimited resource.”
Becoming net-zero took a lot more than just special software and teaching people not to leave the lights on, however. Constructed in 1928 with multiple additions built later, major renovations were needed to bring the Carroll Center to net-zero. The energy leakage on a structure that old was what one would expect, according to Lindgren.
“That building had holes all over it,” said Lindgren.
The process began in 2019 and cost approximately $2 million. A $577,800 grant from the Illinois Clean Energy Foundation was used to reconstruct the Carroll Center using Passive House design principles. Passive House, also known as Passivhaus, principles are rigorous energy-efficient building standards that in part include superinsulation and airtight construction with continuous ventilation.
“It’s the most comfortable building we had,” said Lindgren of the Carroll Center’s internal temperature.
To attain this level of energy efficiency for Carroll Center, the park district enlisted local architect Tom Bassett-Dilley, whose firm has done seven other Passive House-certified projects. Mark Nussbaum, an architectural design engineer from Oak Park, was also brought on. Nussbaum has worked previously with the park district, designing the geothermal heating and cooling system in Pleasant House. Neither Bassett-Dilley nor Nussbaum were available for comment, but Lindgren said they were the “top names for geothermal design in the Midwest.”
The renovation was completed in June 2020, but the park district had to wait until the beginning of this year to submit the Carroll Center’s energy data to NBI due to COVID-19. Temporary programming cessations and occupancy limits required Carroll Center to use far less energy than it would otherwise. Waiting ensured that NBI received accurate energy readings.
With the Carroll Center’s status sealed, the park district has turned its attention to its pending net-zero community recreation center on Madison Street, which was designed and will be built using Passive House principles. Groundbreaking is scheduled for March 14. However, the overall plan is to eventually bring all park district facilities to net-zero, according to Lindgren.
“We actually are working on a greenhouse gas inventory this year,” said Lindgren. “And then we’re going to come up with a path for us to eliminate our emissions.”