Project Team

Other Team Members

AquaZephyr, Ithaca, NY; 607-279-5559; Kendall and Mike Carpenter;;
Rater: Steven Winter Associates, Norwalk, CT; 203-857-0200; Karla Butterfield,;

Ratings, Awards and Recognition


DOE Challenge Home; ENERGY STAR v3; EPA Indoor airPlus, WaterSense; Passive House; LEED for Homes Platinum

HERS Index::

TREE is the third neighborhood to join EcoVillage Ithaca, a group of cohousing developments in northern New York that promote clean, emission-free living in a community setting. TREE is a multifamily, co-housing residence that began construction in 2012 in the North Field of EcoVillage Ithaca. There are 40 separate and diversely-styled homes and apartments within TREE, with sizes ranging from 450 square feet to 1,440 square feet. This village provides residents with a Common House, including a kitchen and dining room, a playroom, a multipurpose room, and guest rooms. The plan for this development was a neighborhood that is durable, affordable, and energy-efficient, to accompany the other EcoVillage Ithaca living communities, SONG and FROG.  The homes within TREE are environmentally sustainable, passive solar, and have an energy consumption of net zero. All of the living residences of EcoVillage Ithaca promote clean living and sustainability as well as community and affordability. 

Quick Facts


Location Ithaca, New York
Building Type Single Family Residence / Community
Project Type Zero Energy
Basis of Performance Claim Modeled, Zero Energy Program

Energy Summary

Energy Data Type Modeled, Zero Energy Program
Renewable Energy System Type(s) Photovoltaics

DOE Challenge Home; ENERGY STAR v3; EPA Indoor airPlus, WaterSense; Passive House; LEED for Homes Platinum

HERS Index 15
Annual renewable energy generated 5,361 kWh/year

Envelope and Mechanicals

Subslab assembly

Rigid insulation installed under slab on grade

Above grade wall assembly

The Double 2x4 stud wall with 5” gap has a 12” depth. Insulation includes R-22 (3.5” at R-6.3/in) closed cell spray foam and R-30 cellulose (8.5” at R-3.5/in) were installed in this double stud wall. Walls are sheathed by ZIPS with taped seams. The exterior finish is a rain screen with cementitious siding.

Air Changes per hour, ACH50 0.42 ACH50