The new microwave in the Mill Creek NetZero Home tries to burn 35 Kg of coal every year to display the time.

When discussing the environment with non-converts, the debate often degenerates to someone commenting “you want us to go back to living in caves”. The sentiment reveals a shocking but widespread ignorance about the vast quantities of energy and materials that we squander. Energy is cheap and ubiquitous, and it seems that humans are doomed to waste whatever is abundant.

The answer to the living in caves comment is that we could reduce our materials and energy consumption by 50% in a heartbeat without touching our standard of living. In fact, we could reduce consumption by over 90% and still live better than kings and emperors did 300 years ago. (Yes, monster truck rallies would have to go. If by “living in caves” you mean “stop driving my Hummer around while Tweeting on my cell phone”, then I stand corrected.)

The microwave at the top of page is state-of-the-art; we purchased it this year from IKEA, a company that makes claims of environmental responsibility. The problem is, it draws four Watts of electricity, all the time, day or night. The useful work that it manages to produce out of the 100 grams of dirty coal that it needs every day is to display a digital clock.  Quick! Raise your hand if you need another clock in your house!  read more... »

The Mill Creek NetZero Home is substantially completed.

The stucco is finished on the outside. We went with a cement-based stucco because of its looks and durability.

Peter Amerongen built a brick wall behind the wood burner. We used the bricks from the foundation of the house that used to be standing on the property. This wall adds more thermal mass (to capture both solar and wood heat) to the house, as well as a bit of history.

 read more... »

Editor’s Note: I’ve written about Rob Dumont in the past. He is one of the fathers of the green building movement, and I’m very pleased to have permission to reprint one of his columns here.

By Rob Dumont

Have there been any recent advances in the area of passive solar heating for residences?

Passive solar heating has been known since the time of Socrates. However, it is only slowly catching on in Canada. Improved windows have made the recent advances possible.

In the 1970s there developed two schools of thought regarding how best to reduce space heating bills in residences using passive means. One school was called the “mass and glass” school. With this approach, large south facing windows would be used along with concrete slabs and heavy construction such as adobe. This school had a lot of proponents coming out of the south-western United States. New Mexico was a hotbed. New Mexico has an especially favourable solar energy climate and relatively mild outdoor temperatures compared with most of Canada. A photo of the David Wright Home in Santa Fe, New Mexico, is shown in Figure 1. In Figure 2 a cross section of the house is shown.

Figure 1. South exposure of the David Wright House in Santa Fe, New Mexico

(Photo Credit: Design for a Limited Planet, Skurka and Naar, 1976)

Figure 2. Cross Section of the David Wright Mass and Glass House

( Credit: Design for a Limited Planet, Skurka and Naar, 1976)  read more... »

The importance of air tightness in building construction cannot be overstated. Very few factors affect energy performance in a cold climate more than air moving in and out of a building.

The Mill Creek Net Zero Home (MCNZ) has achieved an air tightness test result of 0.36 air changes per hour (ACH) at a pressure of 50 Pascal. In other words, when it’s really cold out, which creates a big pressure difference between the inside and the outside of a house, the 0.36 of the air in the MCNZH would leak out and be replaced with cold air over the course of an hour. It has the equivalent of a 13.8 square inch hole in it leaking air all of the time.

To put the number (0.36 ACH @ 50 Pa) into perspective, here are some average numbers:

Source: Biggs et. al. 1987

The 0.36 number is extremely small. In fact, the MCNZH is probably one of the most air tight wooden buildings in the world.  read more... »