The Straw House Blog

So what is an off-grid passive solar home?

Off-grid means that we are not connected to the electrical grid, water, sewer or gas mains. We create our own power with solar collectors and a wind generator. Simon at Generation Solar prepared a Load Analysis with us and specified a system to match. Our kitchen stove and back-up hot water heater are propane fired. On sunny days our primary source of heat is the sun itself coming through the windows and heating the concrete floor. On cloudy days, we have a radiant-in-floor heating system.

Our hot water comes from a combination of two solar hot water heaters and a propane fired boiler, in the summer the propane boiler rarely comes on as the sun provides most of our hot water. In the winter, the boiler must run more frequently in order to make up for the increased number of cloudy days and for the drain brought on by the radiant-in-floor system. A large heat exchanger supplies domestic hot water and heat for the radiant-in-floor heating system.

Passive solar refers to a design philosophy that involves the proper positioning of the house to allow the sun to heat the house in winter but not in the summer. This approach requires the architect to be very precise about roof overhangs and shading, since a mistake can result in a house that acts like a sauna in the summer if too much sun comes through the windows. In our house on the summer solstice the sun comes about four inches into the house. On the winter solstice the sun projects much further into the house - about thirty-four feet.

Basic Info

Our architect is Paul Dowsett of the firm
Solar Power
We used a local firm for the solar power, Generation Solar in Peterborough. Check out our Load Analysis prepared by Generation Solar.
Our heating is coming from a wood burning stove, radiant in-floor heating, and the Sun.
The structure is timber-frame with straw bale infill walls. We hired the fine folks at Camel’s Back Construction to help us with the straw bale building and plastering.
The roof is Galvalum, and was supplied by Havelock Metal.
The windows came from Thermotech Windows of Napean, Ontario.
I am unfortunately in the difficult position of not being able to recommend these windows anymore. At about the 7 or 8 year mark the sealed units started failing. Now most of the south windows have failed and we have been unable to get Thermotech Windows to honour their warranty.
All of our appliances are the most energy efficient that we can find. The only tricky appliance is the refridgerator since that runs the longest each day. The appliances are all major brand names except the dishwasher which is made by Asko.
Most of our lighting is Compact Florescent or Halogen. We have a few LED lights. I found a good source for LED lights and parts (Eurolite) and have built some LED lights myself. I have built a dining room light and hanging lights for the gallery.