The Third Residential EcoVillage Experience (TREE) neighborhood is the newest addition to EcoVillage Ithaca’s (EVI) community. EVI was started in 1997, making it the first co-housing project in New York, and it’s also the largest co-housing project in the world, encompassing of 175 acres of land. Steven Winter Associates, Inc. (SWA) performed pre-construction sustainability consulting, energy analysis, and modeling in addition to being the provider and rater in support of the project’s various certification programs.
The TREE homes have been successfully certified as Passive House Institute US (PHIUS) compliant as well as U.S. Department of Energy Challenge Homes, meeting the program requirements of ENERGY STAR® Version 3.1, EPA’s Indoor airPLUS and WaterSense, and LEED® for Homes Platinum.
Fulfilling the community’s focus on sustainable living, the homeowners at TREE benefit from increased comfort, health, and safety in addition to very low (or non-existent) utility bills. Exceptionally air-tight and well-insulated thermal envelopes minimize the need for heating and cooling. Solar hot water heaters paired with electric storage tanks and low-flow water fixtures reduce energy and water consumption. Energy recovery ventilators (ERVs) provide continuous fresh air while minimizing energy loss.
SWA continues to monitor the homes at TREE and finds that on a community scale the homes generate almost as much kW annually as they consume, nearly achieving “net-zero.” SWA also found that some homeowners were able to generate twice the amount of electricity they used during the peak season (summer). Annual energy savings average 82% lower than standard homes when combining total heating, cooling, water heating, and lighting/appliance energy costs.