More Net Zero Construction Notes

The further along we are getting in this building process the more apparent it’s getting that not many people know what the heck a Net Zero house is. In fact, we have not run across a single person that knew what it was when we tried to explain that we are building one. And this is not only true for common folk not in the home construction industry, but this also applies to all the home product sales people we encountered. From Home Depot and Lowes to flooring, lighting, plumbing, and fireplace specialists. Nobody has any idea what we are talking about when we try explain that we can’t have use propane for cooking or a fireplace and how important it will be to use healthier building materials. They just think we are tree huggers and then proceed to try to change our minds about propane fireplaces and gas ranges. This is prompting me to want to become a Net Zero evangelist. After living in one I may just feel as though I’m “Born Again” and may start preaching to everyone in sight in hopes of getting them to convert.

Sure I can’t get all that excited about it yet because at this point it does seem a little bit like the promise of Heaven. It does sound an awful lot like Heaven actually. A toasty warm house in the Winter and a nice comfortable house in the Summer  . . . all without having to pay energy bills. Fortunately, unlike actually making it to Heaven, in this case I will be able to live through it and tell my story so everyone knows if Heaven does indeed exist. Only time will tell and we are so anxious to find out.

So in my efforts to help spread the word and educate on this Net-Zero technology I want to blog a little here and there to try to explain what makes a Net Zero home special. I already tried to explain the basics of the foundation and basement being built with thick blocks of insulation. And I also mentioned that the walls would be “doubled.” You can see in this picture the outside wall (that has the window framed in it) and then an additional 2×4 wall in front of it making our exterior walls a full foot thick.


Both of these walls will be insulated essentially doubling the amount of insulation that a normal house has. And in between the two insulated walls is what is called a “thermal break” of air. I’m not totally sure how the technology behind this works and perhaps I’ll become more knowledgeable when we get that far so stay tuned on that.

Then there’s the roof. On a conventionally built roof you would normally have insulation only in between the roof trusses. Those trusses might be 2″x10″ or 2″x12″. Our roof trusses are 16″ thick as show below.


Not only are the trusses thicker, but we will have double the plywood under the roofing shingles. Along the same theory as the exterior double walls with a “thermal break” of air in between, the roof is very similar. We have the traditionally covered plywood roof, but then another layer of plywood gets added. The picture below shows the two layers with the gap of air between.


I still haven’t figured out how all this “air” does so much in super insulating the house, but like I said, I’m hoping to become more knowledgeable about how this stuff works. Right now it’s all very new and very fascinating.