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AUSTIN, Texas – Facility managers and operators working to electrify buildings should ensure the building envelope is solid, keeping heat inside the building on cold days and outside on hot days, an expert said this week on a panel at the annual ASHRAE conference.
“One of the biggest problems with existing buildings is that they’re crap,” said Jason Kliwinski, CEO and founder of the Green Building Center. “They’re bad building envelopes, and I don’t care about sophisticated mechanical systems [you have]. If you put it in a bad building envelope, it won’t work.”
Building envelope improvements, such as insulation, air sealing and window retrofits, are crucial first steps to electrifying heating and cooling systems, especially for buildings in cold climates or those with high-efficiency fossil fuel heating systems, according to a 2023 report by the American Council for an Energy Efficient Economy.
Establishing a tight envelope is easier in new construction, Kliwinski said. For example, aa project at Rider University in New Jersey, his team had to electrify a new building on an existing campus to meet LEED Silver for $200 per square foot. His team was able to accomplish this despite constraints, including having to build in nine months to meet the school’s opening deadline and the need to use packaged terminal air conditioners, or PTACs, he said.
“They’re all electric,” he said. “It’s what they had in all their bedrooms, and they didn’t want to rock the boat with their maintenance staff and operations staff. So … how did we get it? If I do conventional construction with PTAC, there’s no way I’m going to meet LEED requirements, let alone anything else. [we] wanted to do”.
His team accomplished the goal by changing the building envelope using structural insulating panels, he said. By using Energy Star panels and the PTAC, the team was able to deliver “an all-electric building on an existing campus that was 25 percent better than code, simply by changing the construction of the building envelope and making a much tighter and better-insulated building,” he said. “The building envelope matters.”
But although it is more difficult to implement in existing buildings, an efficient building envelope gives significant results.
According to the ACEEE report, modest HVAC measures such as air sealing and increasing the quality and thickness of attic insulation can reliably reduce energy use by 12% to 18%. Deeper building modifications that add insulation to walls, basements and edge joists and install more efficient windows could deliver about 33 percent energy savings, according to the report.
Except in heavy process load buildings, such as industrial facilities, modifications to the building envelope can result in a 10 percent to 40 percent reduction in loads, Kliwinski said. “It’s not as glamorous as a new building, [but] the most sustainable [building] “It’s the one that’s never been built,” he said. “Air sealing, HVAC, insulation and window replacements, they’re not glamorous, but that’s what makes existing buildings last another 150 years.”
