The rise of net-zero homes

Read here: http://www.huffingtonpost.ca/david-dodge/netzero-homes_b_5545068.html

How to build your own net-zero home

If you want to build a successful net-zero project it comes down to three key points:

  • Energy conservation
  • Passive solar design
  • Renewable (solar) energy production

Energy Conservation: Your net-zero home needs a high quality building envelope. You need super insulated walls and ceilings, quality energy efficient windows and it all has to be sealed up tight to prevent heat loss. Mike Turner is an engineer at Manasc Isaac Architects who built his own net-zero home: he put R70 insulation in his roof, R50 in his walls and he used quad-paned R8 windows.
The home needs to be far more airtight than the average Canadian home.  An average home has 4.4 air changes per hour – you should be shooting for 0.5 air changes per hour.
Use energy efficient electric heating systems such as an air source heat pump made for cold climates. With no natural gas hook-up you will probably use a high efficiency electric hot water heater.
And needless to say your house has to use as little electricity as possible. That means buying energy efficient appliances, killing phantom loads and being generally mindful of the electricity that you use.

Passive Solar Energy: The site and orientation of your house is key. Face it south and install lots of high performance windows. Build the right sized overhangs that keep out direct summer sun, but still let the lower winter sun shine in. Use a concrete floor for thermal mass to store heat after the sun goes down. Your goal here is to harvest and retain as much free energy as possible.

Energy Production : Once you have created the most energy efficient home you can and harvested as much free passive solar energy as possible then you need to produce the energy you require. Solar photovoltaic panels are the simplest most cost-effective solution for the home today. They have dropped drastically in price over the last few years and your investment will protect you from future electricity prices increases for 25 years.
Buildings and electricity production together account for nearly a quarter of Canada’s greenhouse gas emissions. In one fell swoop the net-zero home addresses a significant chunk of Canada’s greenhouse gas emissions. In a world facing climate change and a volatile energy market the net-zero house is the house we need.