By Kevin Wilcox
A group led by civil engineering students will take an innovative, zero net energy house into a competition organized by the U.S. Department of Energy.
The students’ sun-powered house includes a large deck so that residents can take advantage of California’s temperate climate. Rendering by UC Berkeley/DU Solar Decathlon
April 11, 2017—Later this year an interdisciplinary group of students from the University of California at Berkeley will host a dinner party in Denver. The students are planning the menu and very much looking forward to the evening, but the pressure will be on.
The dinner party is part of the U.S. Department of Energy's Solar Decathlon, a biannual competition in which teams of college students build a full-size functional house powered by solar energy that is judged on the basis of its energy efficiency, innovativeness, design, and market potential. The dinner party is one of the competitions to test that tests how the house performs in the face of real-world activities.
The UC Berkeley team, known as RISE, was founded by Brenton Krieger and Sam Durkin, both seniors in civil and environmental engineering and both inspired by attending an Engineers for a Sustainable World conference as sophomores. The team has grown to 40 members over the past two years and includes students with a variety of majors, including environmental engineering, mechanical engineering, electrical engineering, architecture, environmental design, marketing, legal studies, economics, and business. The team, which is now partnered with the University of Denver, has garnered support from many San Francisco Bay Area design and construction firms, including Simpson Strong-Tie, the CITRIS Foundry, Cahill Contractors, and Overaa Construction.
As the project enters the preconstruction phase, RISE's coleaders for construction, Ruth McGee and Joan Gibbons, both juniors in civil and environmental engineering, are assessing the constructability of the house, working with colleagues at the University of Denver.
"We are building an 816 square foot home," says Gibbons, who notes the competition limits teams to homes of between 600 and 1,000 sq ft. "Our home is a rectangular box that has an attached deck that is the same size, [which] doubles the footprint."
The house has been designed for small, irregular infill lots in Richmond, California. Rendering by UC Berkeley/DU Solar Decathlon
The house has two bedrooms, one bathroom, a kitchen, and a combined dining and living room. The wood-framed structure has been designed to achieve zero net energy status, meaning its solar photovoltaic array will generate more energy than the building requires. This was accomplished, in part, by efficient windows and robust, high-quality insulation.
"That's the first step toward using less energy," Gibbons explains.
RISE designed the house for Richmond, California, a city of about 110,000 residents in Contra Costa County. The city is near a large Chevron refinery and has a largely blue-collar workforce. The house that RISE has designed targets the small, irregular lots that are common there and are ripe for infill development. In an effort to make the house more affordable for Richmond residents, RISE bypassed many of the high-tech gadgets common in some sustainability projects.
In an unusual wrinkle for the Department of Energy competition, RISE has designed its house as a single unit in a potentially stackable system that would accommodate up to three units. The ability to stack the units will make the house more marketable for the San Francisco Bay Area, where real estate prices make small single-family homes unaffordable for many residents.
"We are really excited about the stackable aspect and in trying to solve a problem in the Bay Area," McGee says, noting that solving this problem created another in the form of trying to achieve net zero energy status. "When we add that aspect of multifamily housing, energy usage goes up and roof area goes down. That's been a challenge, but we are working on it.
Another interesting element of the design is a pair of movable walls that run on tracks and hold Murphy beds. Residents can make the most of the small floor plan by folding their beds into the walls and then moving the walls toward the perimeter of the house, Gibbons says.
McGee says the team has begun working with colleagues at the University of Denver who specialize in project management and construction, learning to use the software from that field to exchange ideas remotely.
"They have been helping us review our design and look for those problems that would limit constructability," McGee says. "That's been great. We've also, though, been trying to keep true to our design, finding that middle ground of something constructable [that is] also keeping true to our story and our mission."
This summer, RISE members will travel to Denver and work with their partners there to construct and test the house in preparation for the competition in October. For the decathlon, the team will disassemble the house into modular sections, truck it to the site, and reassemble it. Testing will occur over 10 days.
A total of 1,000 points are available in 10 subcompetitions that in turn are grouped into three categories. The task competitions, including the dinner party and a game night, demonstrate how functional the house is. Monitored performance categories measure the heating and cooling systems, appliances, and the flow of electricity between the house and the utility grid. During jury evaluations, experts rate the houses in such categories as architecture, engineering, and innovation.
Although RISE's design is straightforward compared with some past entries, team members hope to pick up points for the extensive outreach they have done with city leaders and high school students in Richmond and for the marketability of their concept. In fact, when the competition is complete, the house will be reassembled on a city lot, where the team hopes to see it sold to a new homeowner.
"That's really exciting," McGee says.
C. William Ibbs, Ph.D., P.E., M.ASCE, a professor of construction management at Berkeley, and Khalid M. Mosalam, Ph.D., P.E., M.ASCE, the Taisei Professor of Civil Engineering there, are the faculty advisers on the project. Ibbs says the competition is providing the students with a wealth of civil engineering and project management experience in a real-world atmosphere.
"I have taught project management every year. I've done it in a classroom, the textbook way. But here's a laboratory experience where the students get to take the concepts of scheduling or estimating and apply them to a real-life project that they have a vested interest in," Ibbs says. "For me, it's great to see fresh young minds grow and thrive with that type of excitement and thirst for really giving something back to the community."