When Les Zawadzki and Linda Hendry, long-time supporters of the Going Carbon Neutral Project, decided to build their home in Eden Mills, they wanted to incorporate as many “green” technologies as possible.
Eden Mills Going Carbon Neutral was launched in 2007 and residents have been making changes to their energy use ever since.
Zawadzki and Hendry’s new house sets the standard, exceeding building codes and saving energy. The energy-saving started with an extra insulation under heated concrete slab floors – doubling the code requirement from R10 to R20. A vertical layer of rigid foam insulation creates a thermal break around the perimeter of the slab.
Extra attention was given to sealing and insulating critical areas where foundations joined walls and walls joined roofs, including the use of spray foam insulation.
Walls are insulated with Roxul batts. An exterior layer of foil-faced rigid foam insulation minimizes thermal bridging and increases the R value of the wall assembly to R-40.
They also installed triple glazed windows.
The roof deck is sprayed from below with high density polyurethane foam and Roxul provides a total value of R-62.
Spray foam at rim joists and knee walls provides a continuous seal with the roof deck. The roof is finished with aluminum tiles which were chosen for their longevity. Metal roofs embody much less energy than asphalt shingles.
The site of the home was not optimal for taking advantage of passive solar heating but Les and Linda chose a plan with front porches to provide shade on hot summer days. Inside, cellular window coverings provide additional cooling, and keep their home warmer on cold winter nights.
The propane hot water heating system, in-floor on the main floor and radiators upstairs, is zoned to allow rooms to be heated as needed – a central wood stove can also keep the house warm. The water heater also provides domestic hot water to plumbing. Two energy recovery ventilators provide all building exhaust and fresh air supply.
The first winter spent in the home, one of the coldest on record, put this house to the test. It performed as hoped, passing the ultimate ‘Ice Storm’ test – losing only 5 degrees after 2 1/2 days without heat.
On hot and humid days an air-to-air variable refrigerant flow heat pump is ready to cool upstairs rooms and concrete floors.
The 10kW solar PV array on the garage generates about 12,000 kWh per year, more than the average Canadian home consumes in a year.
All wastewater is treated on site to tertiary quality (more than 90% reaction in solids and organic matter) with a Waterloo Biofilter.
Rainwater is captured for watering the gardens. Water for drinking is provided by a well drilled into the limestone bedrock, filtered and UV sterilized.
The couple wanted to show their children that by building ‘greener’, they had tried to do their part for the planet.
“Some people see the big van in our driveway then scoff at the solar panels on our garage and our over-built house, but it’s not an ‘all or nothing’ scenario. You don’t have to go to extremes and walk everywhere or build a greener house to change your life’s CO2 footprint. Start by changing a light bulb, or putting on a sweater and turning your furnace down a couple of degrees. However small or large your part may be, every little bit helps.”
