Project Description

Kallock Residence | Yandow Green Builders

2013 Vermont’s Greenest Building – Residential

Proven annual energy intensive: 18.6 kBtu/sf/yr

This Passiv Haus was designed by Pill-Maharam Architects and built as a 4 module modular home by Preferred Building Systems in Claremont NH. Once the house was set, Yandow Green Builders was the General Contractor in charge of completing the project and making sure the energy efficiency goals were met.

The building envelope consists of four inches high density EPS foam warping all sides of the concrete footings, four inches EPS foam on the outside of the foundation, two inches inside plus 3.5 of cellulose in the interior studded walls giving the foundation walls an R value of about 48. Under slab insulation is 12 inches EPS foam or R-60. The above grade walls consist of a ten inch double studded cavity with dense pack cellulose for insulation plus four inches exterior polyisocyanurate giving the wall assembly an R-valye of 64. The ceilings have loose fill cellulose of 30 inches or R-107. A four inch concrete slab floor was poured in the main living room space to add thermal mass.

The house is heated by a single Mitsubishi FE-18 Hyper Heat Mini split in the main living area. A Zehnder air exchange heat recovery ventilation system provides fresh air to the house with a 88% recovery rate. The system also has a pre-heat/cool soil heat exchange loop incorporated into the ventilation system further tempering and dehumidifying incoming supply air.

The house is also equipped with a two panel solar hot water system with a 52 gallon standard electric hot water heater back up. The windows in the house are triple pane Fiber Tech windows from Canada. The house was sided with CVG eastern hemlock clapboards and has an architectural asphalt shingled main roof and standing seam metal lower roof that wraps around three sides of the house. The house was given a HERS of 29 which means that the energy efficiency strategy taken with this house reduced energy usage by 71%. The house is being fully monitored for its energy performance.


Owner: Bill and Emily Kallock

Construction Manager/General Contractor: Yandow Green Builders

Architect: Pill-Maharam Architects

Mechanical Engineer: Boardman Plumbing and Heating

Structural Engineer: Preferred Building Systems

Energy Consultant: Efficiency Vermont

Electrical Engineer: Spadaccini Electric