For those interested in the technical side of our project, here is a little background:
Passive House / PassivHaus is is the world's leading standard in energy efficient building construction. In order to get a house (or commercial, government, or industrial building) certified by the International Passive House Association, the building must meet three rigorous standards: a maximum energy use per square foot for heating and cooling, a maximum primary energy use per square foot for the house and its occupants, and it must be airtight (no more than 0.6 air changes per hour when pressurized to 50 Pascals - or 0.6 ACH50).
Our house is designed to meet these criteria, and we have employed some less common building methods to do so. First, our foundation will be a 8-inch thick concrete slab without a stem wall or thickened edges, and it will be completely encased in foam insulation. Our walls will be almost 18 inches thick, with mineral wool inside our 2x6 load bearing wall, and cellulose in our 12 inch wide outer wall, formed with manufactured wood trusses. We will have approximately 3 feet of cellulose in our attic. Our windows and doors will be very high quality triple-pane windows with "warm edges" (low heat conducting spacers) between our panes of glass.
Because our house will be essentially airtight (don't worry, we can open the windows), we will be constantly ventilating it at very low air flows, less than 100 cubic feet per minute (CFM). The constant ventilation will replace our entire house volume of air every three hours or so, and maintain a very high indoor air quality. Our heat recovery ventilator (HRV) will heat the incoming air with the outgoing air, so we will lose very little heat in the winter when we bring in the fresh air.
When all is said and done, we should be able to heat the house with the equivalent of a hair dryer! If this interests you, we will continue to post short technical blogs on the different aspects of the house construction as we go along.
This sort of thing beyond interests me. Our house in Scarborough is older (70s) and I've met with a couple energy guys to talk about some of the less expensive stuff to improve how the house works.
ReplyDeleteEventually I want to add an addition that is much more energy sound.
And if you don't mind me asking, about how much will construction cost? And what is the expected ROI given the savings for heating/cooling? I'd love to see this sort of construction become more the norm.
That is great! You should really look at the BEOpt (Building Energy Optimization) software - it is free energy modeling software from the National Renewable Energy Laboratory(NREL). It is very powerful software and fairly easy to use that will help you make the best energy retrofit decisions based on cost/benefit.
ReplyDeleteWe don't know at this point how much construction will cost. Jake is building as much of it as he is able to with his own two hands. We are carefully tracking our costs and will be able to publish that information at the end of the project. We will be an all electric house, which will not necessarily be the least expensive utility option, but we still expect all of our utility bills combined to be less than $50 per month.
That's really awesome. I'll keep that SW in mind as I get closer to doing the addition.
ReplyDeleteLooking forward to more posts :)