Earlier this spring we posted an article on Pre-certified Passive Components: ERV or energy recovery ventilators. The “fresh air machine” of passive homes, including those built by EkoBuilt, ERVs are a vital component and worthy of close inspection. The unit we recommend is the Jablotron Futura Passive ERV and it’s pre-certified by the IPHA.
We fielded a couple of great questions following that post and want to answer them here:
If the ERV is frost-protected down to -20, what happens in areas where the temperature can go down to -30 or -35?
Anytime there are frost conditions, the machines will enter a re-circulation mode to “warm up” the core as required. There will still be incoming fresh air, just less depending on the machine’s efficiency level in extreme cold.
Have you looked at the Panasonic Intellibalance ERV for cold climates? Model FV-10VEC2.
We actually hadn’t installed one of these units before, but at the time this question came in on Facebook we found ourselves on a job where this is what the owner wanted to install, mainly because of cost. They are good units because they are frost protected in the same way that the passive units that we recommend are, however, they consume almost double the electricity and aren’t as efficient. Below we include a side by side comparison at a glance.
Jablotron Future Passive ERV
Power consumption: 0.44 watts/cfm = 444 watts @ 100 cfm
The federal government recently launched its Canada Greener Homes Grant. In brief, the grant provides various incentive options for existing homes to upgrade their energy efficiency, however no grants are available for new homes, even though housing starts in many parts of the country continue to grow (in our own local area, new builds are huge in a hot real estate market). In this article, we ask why the government won’t also support homeowners in building highly energy efficient homes right out of the gate.
Home Energy Facts
According to the Canadian government:
Buildings produce 17% of Canada’s greenhouse gases, including emissions from generating electricity that buildings use. A large part of this is from using fossil fuels to heat and cool our buildings.
40% of emissions from electricity generation is for energy used in our buildings.
The federal government will support improving the energy efficiency of our homes and buildings.
A passive house has 3 times the insulation and 4 times the air-tightness of a home built to current code.
Passive walls = R 75
Code walls = R 27
Passive roof = R 110
Code Roof = R 32
Passive air tightness = 0.6 ach*
Code air tightness = 2.5 ach*
*ACH = air changes per hour
With the above info in mind, Passive homes are known to save 80-90% energy per house.
Energy Efficiency at What Cost?
Building to the passive standard does cost 5 to 10% more per build, and this is our point in a nutshell. If incentives were available for newly built energy-efficient passive homes, then more people would be building them, a direct benefit in reaching Canada’s climate change goals. It seems unfair and really a touch irresponsible that only retrofitting of existing homes is being supported when so many people are in the position of having to choose a new build.
This scenario is bad for climate change, bad for meeting our emission reduction targets, and simply bad policy. Shouldn’t we have equivalent incentives available to all home buyers?
Canada’s federal government offers point-of-sale incentives of $2,500 to $5,000 for consumers who buy or lease an electric vehicle — why doesn’t the same thinking apply to new home builds when we live in communities bristling with the construction of new homes?
More money in your pocket
There is another reason why building passive matters so much for home owners, and it’s one we find can get a bit lost in the noise and excitement of building. Passive homes are much cheaper to run. Using so much less energy means that energy bills are correspondingly less. From the young family just starting out to the retired couple downsizing, who wouldn’t welcome smaller monthly bills for running a comfortable and healthy home?
A carbon free future
We are hoping to continue this discussion because without new-build home incentives for the most energy efficient homes possible, how will we really start moving towards a carbon free future?
In 2020 we sold our first model home, the hugely popular Trillium model that we had built west of Ottawa as a showcase for our passive house offering. This is an overview of that build. Our new model home isn’t ready yet, but you can read about it here.
The Trillium energy efficient house plan is a two-storey home with a really unique layout, including single storey “wings” that were used for the kitchen and master suite, respectively.
The core two-storey section of the home houses living spaces and a powder room on the main level and three bedrooms and a bathroom on the upper level.
The street facing side of the home features smaller windows, while the living areas at the rear side of the home feature much larger windows and patio doors.
One question we often field is whether our passive house kit is the same as a prefab house. It’s not. It’s something much better, in our view, and here’s why:
Unlike a prefabricated house, which comes straight from the factory ready for final assembly on your property or site, our material kits provide quality materials installed in the correct steps and the option to be as involved as you like in the build. These are quite significant differences.
Our weathertight material kit can be shipped across North America, and can be assembled by any experienced carpenter. It’s down to you and the details of your project to decide on foundation and finishes.
We’ll state our bias upfront: we think that our passive house kits win hands down over prefab assemblies, particularly for our northern climate where weathertight wall assemblies matter a great deal.
Prefab Homes: The Cons
Transport – large prefab walls require multiple large trucks, adding cost to the project’s bottom line.
Site access – large trucks often have trouble accessing building sites, requiring additional vehicles and steps at increased cost.
Build integrity – insulation in prefab walls demand just the right weather conditions during transport and assembly.
Assembly & foundation issues – prefab buildings need cranes for assembly, which are costly. This cost is often driven up by site / foundation irregularities affecting installation.
Hidden costs – fully prefabricated homes are marketed as being cheap and quick, but as the points above illustrate, at what additional cost?
Air leakage – prefab systems come with just one chance to seal the building with exterior tape, compared to the stringent triple-protection of a passive house build (vapor barrier, air barrier, and water barrier).
Mechanical penetrations – there are a number of items required to pass through walls, such as plumbing vent pipe, exterior light and outlet wiring, HRV supply and exhaust lines, heat pump lines, etc. Prefab walls containing insulation will compromise thermal break at all of these points, making the building envelope far inferior.
Passive House Kits: The Benefits
Flexible, local – our kits allow you to be as involved as you like, as well as to involve local builders and tradespeople.
Transport – we partner with national carriers and distributors, allowing us to minimize delivery and travel distances regardless of property location.
Site access, build versatility – our weathertight material kit is provided unassembled, simplifying delivery options and providing flexibility for adapting to building site conditions.
Sensible construction – insulation isn’t installed in the roof and walls until the building is proven to be weather-tight; an on-site build just makes more sense.
Quality assurance – the integrity of installed materials is best accomplished when they are installed together. The vapor barrier goes first, followed by the air barrier, and then the water barrier. The only method of quality integration is with a site-built kit, not a pieced-together panelized home.
Customizable – we offer the choice of structural wall assembly: standard wood frame or optional internal timber-frame core.
Insulation – this is the main component designed to keep the building easy to heat and cool, and to remain problem-free. Any super-insulated building needs to have a vapor permeable system in place for the wall to maintain dryness. EkoBuilt wall insulation R75, roof insulation R120.
Wind tight: an EkoBuilt PassiveHouse is guaranteed to be under 0.6ACH (air exchange per hour). Any modern building should be able to perform to this degree of air-tightness.
Timing – pre-assembled kit elements achieve an accelerated build timeframe.
We think you’ll find that the quality and energy efficiency that can be achieved by building on-site far outweighs the apparent convenience of a fully pre-fabricated house. Contact us to find out more.
As we talked about in our last post on passive windows and doors, pre-certified components are a thing. They make meeting the passive house standard that much easier (whether you plan to officially certify your home or not).
It’s been a few years since we last profiled our certified passive window and door supplier of choice. In this post, we revisit why we’re so passionate about the passive house standard above all, and profile Munster Joinery. We also highlight where to get these windows and doors in the United States and answer some commonly asked questions about windows.
Yes, we can and do provide our EkoBuilt Passive House kits and plans to US homeowners!
We love that the passion for building passive continues across Canada as well as south of the border. We hear regularly from home owners in the United States keen to build with our weathertight material kit and super energy efficient plans. With governments around the globe now talking about carbon free futures, a passive home is more relevant than ever. We are pleased to share a couple of projects happening in the US this year.
You can always find a larger square foot home more cheaply from a developer, but as soon as you move into one of these spaces and notice the poor air quality, cheap finishes, and expensive utility bills, it is easy to become quickly dissatisfied with the space. Why compromise?