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EcoVillage at Ithaca Plans a Passivhaus Branch

The cohousing community’s third project will add 40 units, some built to the Passivhaus standard, to the 60 units already in place

Posted on Sep 28 2011 by Richard Defendorf

The online directory of the CohousingDevelopment pattern in which multiple (typically 8 to 30) privately owned houses or housing units are clustered together with some commonly owned spaces, such as a common workshop, greenhouse, etc. Automobiles are typically kept to the perimeter of the community, creating a protected area within where children can play. Usually, residents are closely involved in all aspects of the development, from site selection to financing and design. Association of the United States lists more than 240 cohousing projects. Some of them are still forming. Some, under the auspices of umbrella groups, are established but have not yet secured building sites. Many others were completed long ago, a few are now being retrofitted, and some are even expanding.

One such veteran cohousing community, EcoVillage at Ithaca, in central upstate New York, completed a 30-unit neighborhood in 1996, another 30-unit neighborhood in 2004, and now is planning a third, called Third Residential EcoVillage Experience, or TREE, that will add 40 more units to the community, including at least 25 homes that the development team aims to build to the PassivhausA residential building construction standard requiring very low levels of air leakage, very high levels of insulation, and windows with a very low U-factor. Developed in the early 1990s by Bo Adamson and Wolfgang Feist, the standard is now promoted by the Passivhaus Institut in Darmstadt, Germany. To meet the standard, a home must have an infiltration rate no greater than 0.60 AC/H @ 50 pascals, a maximum annual heating energy use of 15 kWh per square meter (4,755 Btu per square foot), a maximum annual cooling energy use of 15 kWh per square meter (1.39 kWh per square foot), and maximum source energy use for all purposes of 120 kWh per square meter (11.1 kWh per square foot). The standard recommends, but does not require, a maximum design heating load of 10 W per square meter and windows with a maximum U-factor of 0.14. The Passivhaus standard was developed for buildings in central and northern Europe; efforts are underway to clarify the best techniques to achieve the standard for buildings in hot climates. standard.

Eight of the 40 units will be constructed as duplexes (the community’s existing homes are all duplexes), 17 will be detached homes, and 15 units will be built into a common house that will serve as the neighborhood’s centerpiece. Construction is expected to begin next year, with the last units completed in early 2013.

Small homes, small prices
EcoVillage has long supplemented its energy needs with photovoltaic(PV) Generation of electricity directly from sunlight. A photovoltaic cell has no moving parts; electrons are energized by sunlight and result in current flow. power, and TREE likely will be no different. But even those units not built to the Passivhaus standard probably won’t be energy guzzlers: the homes will range from 450-sq.-ft. studios to 1,440-sq.-ft. four-bedrooms.

The project team also is striving for affordability, with prices ranging from $80,000 for a studio to $235,000 for a four-bedroom. As noted in a recent article published by the Ithaca Journal, the village has explored working with the National Affordable Cohousing Organization, which could purchase some of the units from the village and make those units affordable as rentals.

"We will be the first place in the Americas that will have three cohousing communities and one of the only ones in the world," EcoVillage Executive Director Liz Walker told the paper. "At every step, we are doing pioneering work and that is part of what makes this all so special. Every day, there is something new."

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Image Credits:

  1. EcoVillage at Ithaca
  2. Energy Design Update

Sep 29, 2011 6:55 AM ET

Great project
by James Morgan

Envious of those construction costs. Wish we could come close here in the NC RDU area.

But I have to challenge Liz Walker's bragging rights on multiple co-housing communities, at least in spirit if not by the letter of municipal boundaries. We have four in a more or less continuous urban area - Solterra and Eno Commons in Durham, and Arcadia and Pacifica in Carrboro.

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