Category Archives: problems

Wolfe Island Passive House Performance – Final Report

We have received a copy of Anthony Mach’s final report on our place, part of a comparative study that also looks at another passive house project in Peterborough, Ontario. We’re not going to comment on the Peterborough project because we know very little about it and it’s very different to ours so, with Anthony’s permission, I will just highlight some parts of the report as it relates to this house.
Anthony’s report compares our Passive House to the new highest Canadian code standards. Bear this in mind, because the average Canadian (or US) house wouldn’t have been built to anything like those latter standards, and as for the average older house on Wolfe Island… well, let’s just say, you could probably punch a hole through the wall of many houses here, our old one included!
I think Anthony has been somewhat conservative with his estimate of the R-value of the walls and ceiling, which based on the whole assembly (including the CLT, which has an R value of 4-5 on its own, and siding) would be nearer 50 in my view. But conservative estimates are better than exaggerated claims for testing efficiency. This leads to some estimates for the house’s performance:
I’m also surprised by how much heat loss there is through the walls in these estimates, but apart from my feelings about R-values, I don’t have any basis for challenging this – it just seems like more than I would have expected. But the important thing is that our energy consumption is reduced dramatically.
I think here there is a little more erring on the side of conservatism here – basically Anthony has estimated the energy consumption of our appliance and lights to be the same as the 2017 Code standard, but we are using all LED lighting now – although we weren’t all the time when the measurements were taken in the winter as the electricians had just used a whole range of conventional bulbs – and we have fewer, smaller and more efficient appliances compared to the average household. We will have to test this empirically through the year via our bills! Anthony’s current estimate for our annual electrical bills has them at almost half the best you would get from a 2017 Code-standard house:
Of course, one of the problems with bills is that you can only reduce them so far: the majority of our bill is not use charges but fixed fees and delivery charges, over which we have no control, unless and until we are totally off-grid, which brings us to…
Green House Gas Emissions
On Green House Gas emissions, I would imagine that once we’ve installed the Solar Thermal and Solar PV panels (probably this summer, although it depends on costs), and possibly some other wind-based generation, this will further reduce our electrical draw draw from the grid and our costs, and therefore also our GHG emissions. Our eventual aim is to have zero energy bills and net zero GHG emissions.
Winter Performance
You can see more detail about the winter temperature and humidity in the preliminary results. While, as Anthony notes, we found the house perfectly comfortable over the winter, I think the house will be a little warmer next time around. Because it was uninhabited until late November and there was no heating for a while after that, the house never really built up the sustained warmth that would thereafter be preserved to a greater degree by the insulation etc. We shall see!
NB: the December average is significantly different because note that we were away for much of the second half of the month, and had the HRV set on its lowest setting and the thermostat at around 13ºC.
Summer Cooling
Anthony’s report doesn’t just cover what actually happened over winter, it also uses PHPP (Passive House software) modelling to estimate what would happen in the rest of the year. Of particular note is that the model predicts mechanical cooling will be necessary in July and August.
The HRV certainly does not function effectively as a cooling system so far as we can tell. But I’m yet to be convinced by the need for mechanical cooling. Although the primary rationale for the orientation of the house and the window size and placement was Fall-Winter-Spring heating, the house was also designed to take advantage of the prevailing wind direction and for both effective stack and cross-ventilation. Simply by opening the windows (and turning off the HRV), we think we will be able to create significant cooling. Indeed that’s how things are working now (late June) even though we are only opening the windows on the tilt setting to minimize the chances of insect entry until we have had the screens manufactured (very soon). So I think we might be able to manage without any mechanical cooling. The PHPP calculations done by Malcolm Isaacs prior to the building had said the same thing – his solution was to have a large fan which we could place temporarily at one of the attic windows in summer, and use occasionally to do an almost full-house air replacement. This may be as far as we go…
The Verdict
There is a lot more in the report, but overall, Anthony characterizes our project as a successful one, and having been here, we know he like the place!
We are really grateful to Anthony for carrying out this research, as we never would have had such a detailed understanding of the house without it.

 

Building waste, reuse and recycling

Now we’ve finished all the basics, we’re back from being away, the snow has gone and the rain has finally stopped, it’s time to think about clearing the site, landscaping and planting. The immediate thing that strikes you is just how much ‘stuff’ there is that’s left over when you build a house. And this is even given all the steps we’ve taken to reduce waste, particularly with the insulation where the Chris and his crew were superb at making use of almost every piece of off-cut wood fibre. And yet… ‘Ecological’ products come wrapped in layers of plastic. Roofers leave inexplicably large pieces of off-cut steel lying around. Siding comes in job lots that always seem to require one more pallet than you thought you would need. And so on. It would be really nice if you could plan the entire house to be precise about the amounts of materials you would need and would fit with commercially-available quantities, but that’s just not feasible.

So after the trials and tribulations of building, the challenges, the fun and the romance, there seems to be a of ‘waste’ to deal with. And there will be more once we start demolishing the old house. Anything that’s unused or reusable, we’re going to store in the barn. Material that could be of use in maintaining the new house (like any uninstalled siding, decking planks etc.), we’ll keep. We also have some plans for greenhouses and chicken coops, and so there’s plenty of stuff we can use for those projects. Other material, we will offer to anyone who thinks they can make use of it. Some, we can recycle, but unfortunately there will be some sent to landfill – as little as we can, but it seems very difficult to do an entirely ‘zero waste’ build within the current system.

But first of all, it all this stuff to be sorted out. So that’s what I’ll be doing over the coming week!

Warm Inside

The coldest night we’ve had in the passive house so far saw the outside temperature drop to -20ºC (and that’s before we take account of wind chill). However, inside it was 15ºC when we got up, and with a couple of hours of the little room heater and the sunshine today, we’re now up to 19ºC. Plus, the place feels much warmer than this. It’s hard to describe what this means over and above physical temperature, but it’s something to do with the evenness of the temperature and the aesthetic warmth of the wood.

One other issue, apart from the Motura door seal which we discussed yesterday, is the lock on the front door. This might be passive house certified and highly insulated but the lock is essentially a metal tube which goes from one side of the door to the other, in other words a cold bridge surrounding an air leak. It might be a very small example of both, but the ice that forms on the inside of the lock when it’s as cold as it was last night, shows the truth!