Comfortable, Resilient Net-Zero Buildings Aren’t Just Residential

Hampshire College’s R.W. Kern Center achieved zero net energy building status due to its passive solar orientation, high levels of insulation, airtight envelope and triple glazed windows. The building also includes air source heat pumps, and a 118-kW rooftop solar array capable of generating more than enough energy to meet the center’s needs on an annual basis.

Marc Rosenbaum, instructor of HeatSpring’s Zero Net Energy Buildings course, was the environmental energy consultant for the R.W. Kern Center, which was certified by the Living Building Challenge. The organization focuses on 20 goals, including objectives about energy use, social equity and chemicals that builders should avoid, says Rosenbaum.  

With this certification, the Kern Center demonstrates that zero net energy– a building’s ability to produce as much energy as it consumes–is not just for residential buildings, he says. As part of his course, he provides a case study of the 17,000-square-foot building, which was completed in 2016 and includes classrooms, the college’s admissions office and a cafe.

All That’s Important in a Zero Net Energy Building

“It has all the components taught in the course; a super insulated building enclosure, high levels of insulation and really good windows and doors,” he says. It’s very air tight, and the ventilation system is based on energy recovery ventilators, which minimize ventilation loads.

Also featured in the center are super efficient lighting and plenty of daylight. 

In low-energy non-residential buildings, lighting represents a higher proportion of the energy load, so it was important to aim for “lights off” during the day, Rosenbaum says.

Send Excess Energy to the Utility or Store it?

The Kern Center sends excess energy to the utility through a net metering arrangement. On an annual basis, it produces at least as much energy as it consumes.

Being connected to the utility and using net metering makes more sense than going completely off grid, says Rosenbaum. “If you have an off-grid building, you need twice as much solar, which I don’t think is a good societal choice.  It’s better to be net zero and send out the excess.”  Owners of off-grid buildings can only take advantage of the excess energy they produce by acquiring energy storage, which can be expensive.

Market Growing for Resilient, Healthy Homes

While Rosenbaum focuses on how larger buildings can now become zero net energy, he also notes that the market is growing for zero net energy residential buildings.  He lives in a 1300-square-foot house that is super insulated and has a 5 kW solar system that powers the house and his plug-in hybrid car.

The COVID-19 crisis and increases in the numbers of wildfires and power outages have boosted demand for more efficient and resilient homes like his.  

A Home that Supports Occupants Safely

“People are buying houses in resort communities and outside of New York City to get what feels like a safer or more resilient living situation,” he says. A resilient home is a home that supports its occupants safety. “If power went out, my house would get cold more slowly than houses around me. And on sunny days it just warms up because the glass is on the south side.”

People want homes that include many of the non-energy features of zero net energy buildings, Rosenbaum says. That includes comfort and a healthy environment, features that often are byproducts of efficiency.

“The thing that people value most is that they’re building a safe, healthy and comfortable place for their family,” he says.

First Conference Call with Marc on Sunday October 11th

Come join Marc for a 10-week session in his recently updated Zero Net Energy Buildings course which begins soon. Enroll today and get access to all of the course materials right away, calls with Marc each week during the 10-week instructor-led session.