ÉcoTerra™,
a 1,500 square-foot home in Eastman Quebec, not only produces as much energy
as it consumes in a year (a net-zero energy home), but also features a healthy
indoor environment, low environmental impact, significant resource conservation
and affordability. Factory pre-engineered modular sections were used to optimize
construction quality and reduce construction as well as environmental impact at
the site.
The R-2000 house, by builder-developer Les industries Ste-Anne de la Rochelle,
Inc. (Alouette Homes), was chosen as one of the winners in Canada Mortgage and
Housing Corporations’ Equilibrium project. Formerly known as the Net-Zero Energy
Healthy Housing program, the initiative brings the private and public sectors
together to develop homes, and eventually communities, that address occupant
health and comfort, energy efficiency, renewable energy production, resource
conservation, reduced environmental impact and affordability. Houses built with
the assistance of the program are monitored to assess their performance, and are
open to the public for tours.
The total annual energy requirement for the home is predicted to be equal to the
on-site annual production from renewable energy sources: active and passive
solar space and water heat, a geothermal heat pump and photovoltaic electrical
panels. That energy requirement is predicted to be only 17 percent of that for
the average Canadian home.
ÉcoTerra™ includes a living room, dining room, kitchen and two-piece bath with
laundry on the main floor, and two bedrooms, an office and four-piece bath on
the second floor. The second floor is constructed with movable interior walls in
order to accommodate the occupants’ changing needs.
The well-insulated building envelope significantly reduces space heating
requirements and the house is oriented to maximize solar gain. Special attention
has been given to daylighting, with large south-facing windows and open spaces
that increase light penetration to the main floor. Roof overhangs are used to
prevent overheating from solar gain. Energy-efficient, triple- glazed, low-e,
argon-filled windows contribute to the reduction in heat loss. Thermal mass
materials, which store heat and moderate interior heat fluctuations, include the
concrete floor and half wall in the family room, and concrete slab and walls in
the basement. Drain water that would otherwise escape from the house is captured
with a heat recovery exchanger.
ÉcoTerra™ utilizes a building integrated photovoltaic system combined with a
heat recovery system. A three kW Uni-Solar PV array, composed of 21 PV film
sheets laminated to a standing-seam metal roof, is connected to a DC/AC
inverter. The inverter connects through the electricity meter to the grid. Solar
heat generated at the roof-top system is captured and then distributed in the
home, assisting with space heating, domestic water heating and clothes drying.
Removing this excess heat from the vicinity of the array also improves its
efficiency. To further reduce energy costs, a three-ton, two-stage geothermal
heat pump provides space and water heating.
On the 2.7-acre forested lot, a system of streams and storm water management
ponds provide erosion control. A rain barrel system captures roof run-off for
garden watering.
The airtight construction, combined with a heat recovery ventilator, is also a
key health feature of the home. In addition, the pre-engineered modular
construction allows many interior finishes to be factory-applied, which
decreased toxic fumes on the worksite and greatly improves indoor air quality.
This article was published in Natural Life Magazine in 2008.