Without breaking the bank

Oh yes, there’s that. Our goal is to not only build ourselves a healthy home we will love for years and years to come, it’s also to show that there are potential monetary benefits to building in this manner. We want the construction price to be achievable for a custom modest house. Even if construction house is slightly higher than a typical custom house, the energy savings will offset those costs and pay for themselves in a short amount of time. This is what we hope and believe we will be able to show. 

Does it just come down to where we spend the money? Do we invest in the walls and windows and skimp on the finishes? Likely we will have to. And we’re totally happy to live with concrete or plywood floors, Ikea kitchens, what have you. But how far will we have to go if we want to achieve Passivhaus certification? Should we go for certification or is it enough to simply apply good Passivhaus principals to our design and build and forgo the difficult certification process? 

How far are we willing to go and where do we draw the line? 

Upgrading our windows from really good triple-glazed windows to really really good windows could cost us an extra $30,000. Building 24” thick walls instead of 18” could be another 20 thousand. Would we rather forgo the negligible window difference and install a grey water recovery system? What would improve our lives the greater? We do not have very deep pockets and not a lot of room for error. So if we go for certification and come close, but don’t get it, was it worth it? These are all questions weighing on our minds. When we have the answers, we’ll let you know. 

Why can’t we be friends? Good design and Passivhaus

Can a Passivhaus building also win over architecture fans? Are good design principals and Passivhaus principals mutually exclusive? We certainly hope not. But as we are in the throws of designing our home, we are discovering that it ain’t easy being green.

Mark and I finally arrived at a design we loved. We went over to the lot, staked it out, and were generally feeling pretty fantastic about what we had come up with. *Pat on back* That is, until Mark started the energy modelling. The numbers weren’t looking as good as we had hoped. If we increase the thickness of our walls (from 18” to 24”), put in top-of-the-line triple-glazed windows, and added a sources of heat (radiant floors/ducting), we’d still be borderline for Passivhaus. 

If we had a large lot, with great exposure and few neighbours – building a Passivhaus that met our architectural/design snobbery requirements would be no promlemo. Our lot, however, poses several large challenges in terms of Passivhaus design:

1. It’s narrow. The narrow shape of our lot wills a narrow house plan. Plus we need to push the house as far over to the North side of the lot as possible, to allow for better exposure on the South-facing windows – further increasing the need for a narrow house plan. However, for best energy performance, a more square shape is preferable. How do we create more of a square plan while maximizing solar gain on those South windows?
2. Limiting distance. Limiting distance in the building code restricts the number of windows we are allowed to have on a side facade facing neighbours. Our South facade just so happens to be along the side of the house, facing the orange neighbours. So depending on the area of our south facade, we’re only allowed a small fraction of it to be windowed. We’re looking at 10–12% window coverage. This is pretty piddly compared to the area of window we would like to have. 

Never to back down from a challenge, we are readdressing the design to see what changes we might be able to make. Hopefully just tweaks, and not a major overhaul. We may feel slightly deflated by this set back, but are still determined to make friends out of these two…without breaking the bank…