Team Middlebury is one of the twenty teams chosen to compete in this year’s US Department of Energy Solar Decathlon competition and their entry is the design and building of a socially and environmentally sustainable house called the InSite house. The team is made up of more than 100 Middlebury College undergraduate students from over 25 different academic disciplines. The finished two bedroom and one bathroom house will measure 956 square feet, while the building costs are $250,000.
One of the more innovative ideas of the InSite project team is the so-called Solar Path. Instead of placing them on the roof, the team will use solar panels to cover the outside path leading between the town of Middlebury and the site where the house will stand. This path, it will serve the double purpose of harvesting solar energy while encouraging walkability, which is one of the key goals of social sustainability.
The InSite house will also feature an 18-inch green roof on the north sloping side, which will be covered by sedum plants. This hardy succulent plant is one of the best choices when it comes to choosing roof covering for green roofs, since it offers natural insulation, helps manage storm water runoff and sequester carbon. Sedum roofs can even last longer than conventional roofs and benefit the environment as a carbon sink, as well as by encouraging biodiversity.
The InSite house also aims to encourage a more social lifestyle of the occupants. For this reason the private spaces (bedrooms) will be small compared to the public spaces (living room, kitchen dining room). With this goal in mind, the house will have three distinctive areas, namely the private space, the public space, and the so-called “chimney core.”
The “chimney core” is a modular unit, which acts as the central point, or core for all the energy and water needs of the house. It contains all the active mechanical systems in the house, and enables passive cooling through the so-called “chimney-effect”. This effect is achieved by placing the vents and windows high in the mechanical module to allow the escape of hot air, while the vents placed low on the shaded north side allow cool air to enter and flow through the house on hot days. All appliances are centralized next to the mechanical chimney, which will greatly reduce the amount of plumbing, wiring and ductwork needed.
The tight building envelope of the house is made up of a 14-inch cellulose insulation, a high-performance Intello vapor retarder, FSC-certified plywood, locally-sourced reclaimed barn wood, and Huber Zip panels, which are used in the 48 wall panels and provide an integrated sheathing-air penetration barrier to ensure a tight, leak-free envelope.
The InSite house design also includes electric tankless water heaters, which only heat as much water as is needed and therefore eliminate stand-by loss and cycling-loss of energy and can reduce water heating costs by as much as 60%. The team opted to install ECOSMART tankless water heaters, which are also 99.8% energy efficient. To reduce the travel time of water through pipes, and the resultant loss of heat, the heaters are place close to the points of use.