1,000 Square Feet of Green
The Solar Decathlon was an inspiring collection of 19 net-zero homes designed by teams of university students, on display in September 2013 at Great Park Irvine. The next event is scheduled for 2015, and I would wholeheartedly recommend taking family and friends for inspiration on how to build houses today.
It is amazing what 1,000 square feet can do. These teams of students made 1,000 square feet into comfortable 2-bedroom houses through the use of flexible multi-purpose rooms and furnishings (many provided by Resource Furniture in Los Angeles) and wrap-around outdoor living spaces. The SHADE house, for instance, staffed by Arizona State and U. New Mexico students, made use of a queen bed/desk convertible that rotates 180 degrees to hide the desk and shelves and fold out the bed. This unit makes possible a multi-purpose room that can double as a guest room and office.
Each house seemed designed for a unique climate, typically the one the students lived in. The Alberta house, for instance, was designed for remote housing of workers in the mineral industry and for the extreme climate there. The Kentucky/Indiana house was built to be a shelter-in-place building in tornado-prone areas. And the Arizona/New Mexico house took cues from cacti found in the desert to minimize heat gain and handle extreme heat. It was a significant finding that houses could be designed to be net-zero energy in so many different climates.
Hot technologies this year included heat-recovery ventilators, LED lights, energy monitoring apps, phase-change materials, southern exposure shading, and creative use of PV panels. Middlebury (pictured) and Arizona/New Mexico both used the PV panels as a shading device over their South-facing decks, and the Kentucky/Indiana home made a V-shaped roof with the northern side tilted to catch the Sun in the southern sky and the water caught in the center funneled into a catchment system.
Houses We Loved
1) Norwich University Ohio
The Delta T-90 is designed to maintain a delta-T or temperature difference between inside and out of 90 degrees in extreme weather. It has enhanced insulation 16 inches thick with staggered studs, creative retractable sun shades on the windows (pictured), and flat-panel PV panels, which the students explained work better in low light, do not require perfect orientation to the Sun, and are lighter and thus
require less structural support. On the marketing side, they also had the most compelling hand-out to visitors – a cootie-catcher that folds in various directions to show different features of the house.
2) Arizona State/U. New Mexico
The collaboration of desert schools resulted in a versatile home with a large solar canopy on the South that created a shaded desert ecosystem underneath. The multi-purpose space is pictured with a hideaway bed that doubles as a desk during the day. And they used gorgeous materials to create a sumptuous bathroom, which is more possible with smaller spaces. They interestingly used capillary tubes embedded in a plaster ceiling for temperature control. The plaster looked great, but the house came in last place for the Comfort Zone test that required the teams to maintain the environment between 71-76 degrees and less than 60% relative humidity.
The house from Stanford students looked like it would be at home in the Bay Area’s affluent communities, and the nearby presence of Silicon Valley showed itself in the core concept. They built all mechanical systems into a central core of the home, including plumbing, appliances, and climate control systems. The living spaces were built around the core, which allows for flexibility of design that was a compelling idea. They also documented the energy use and cost of the equipment well, which gives visitors to the house and the website ideas for their projects.
Teams were encouraged to count costs as they put together these houses, and the winning team on this measure was Norwich University, with a cost of $168,000. Stanford ($234,000) and Kentucky/Indiana ($248,000) also performed well on this measure. Nine other teams scored within 5% of these top 3 teams.
It was one thing to perform to net-zero in September in Southern California. Quite another thing will be how these houses perform in their home climates over the course of a year. But the village as a whole produced 6,208 kWH and used only 4,159 kWH over the course of the two-weeks in operation. It was interesting to note that the one rainy day during competition resulted in energy production that was only 30% of full sunny-day production. On this measure, the top performing houses were Austria (the overall winner), Arizona/New Mexico, Missouri S&T, and Alberta, each of which produced more than 100 kWH more than they used over the period.
Comfort & Climate Control
The top performing teams on this score were Santa Clara, Washington DC, Czech Republic, Las Vegas, Alberta, Ontario, and Middlebury. With scores of visitors walking through the homes, it is quite a challenge no doubt to control temperatures inside the homes to below 76 degrees on a warm Southern California day, but these homes performed well.
The top scoring teams in the overall competition were Austria, Las Vegas, Czech Republic, Stevens, Stanford, Ontario, Washington DC, and Middlebury.
The dedication of the student teams was clear to see, with many having devoted their entire summer break and the year prior designing and building the house on campus, only to disassemble it, ship it to California, and rebuild it. It was clear they were enjoying the team experience, the chance to meet other teams from around the world, and the chance to apply their studies to a cause they believed in. The contest lent itself to socializing, too, with the Home Entertainment contest requiring teams to host other teams for dinner prepared in their house with their appliances. Teams from Santa Clara, Washington DC, Middlebury, Austria, North Carolina, and Ontario won this “host with the most” contest. Likely many of the students left Southern California with job offers and contacts from other teams that will be valuable to them as they chart their futures.