Hadley Net Zero

Project PDF

This home was designed for two professors who wanted fossil fuel-free living that would sustain them into retirement.

The design takes advantage of both active solar energy to provide for electric loads, and passive solar to supply daylight and warmth. Through careful study and planning, a simplicity of form and materials were selected to promote durability and resilience, assuring a long-lasting, low maintenance home for aging in place.

Project Details

The lot is adjacent to endangered species habitat, and had a tall row of pine trees which could not be cleared, and so siting the house to receive an adequate amount of solar exposure was a complex puzzle. C&H built a 3D massing model and experimented with a series of sun studies to arrive at the ideal building location and orientation within the prescribed restraints.

The roof was mounted with a 22kW photovoltaic array. While this may seem like a large supply of electricity, C&H was still careful to maintain low loads inside the building to assure its electric air source heat pump heating and cooling system, as well as the electric car, were assured of adequate supply at all times.

The Owners have installed a TED electric monitoring system that tracks energy consumption and generation. According to data available for August – November 2011, the monthly average for PV generated electricity was 2625kwh, while the home only used between 540 and 700 kwh/mo. This usage includes the Owners’ electric car, which draws about 170 kwh/mo.

The walls are double stud filled with cellulose insulation to a thermal rating of R-40. The roof is R-50 and windows are triple glazed. Roof overhangs are sized to limit direct sun in the summer, and welcome in low angle winter light. A test to the building’s passive performance came in a surprising October snow storm that knocked out electricity to the whole region. The house lost power for two days and two nights. Over that time, outdoor temperature dipped into the low 20s, and averaged in the 30s. The Owners reported that the house didn’t feel chilly – they didn’t even feel the need to fire up their wood stove.

 

The conditioned walk-out basement is fitted with an efficient wood burning stove. Locating this appliance on the lower level mitigates overheating, which tends to be an issue in high performance buildings with wood heat, and also allows natural convection to circulate the heat produced throughout the building without the need for mechanical assistance.

Books are an important part of the owner’s lives, and they have many of them. Rather than sequestering the collection in a separate room, floor to ceiling bookcases were designed as both storage and space delineation in the main living space. These become an integral feature of the home’s character, reflecting the character of our clients.

A tree, harvested from the site, is used as a playful, space-defining structural column in the sitting room – its retained branching rising high into the lofty space above.

Project Team

Architect

C&H Architects, Amherst MA

Constructor

Wright Builders, Northampton MA

Landscape Architect

Systems Consultant

Energysmiths, West Tisbury MA

Structural Engineer

Whetstone Engineering, Wendell MA

Mechanical Engineering

Civil Engineering

S.K. Kimberley Engineering, Colrain, MA