This month’s profile is a mixed-use multi-unit residential building in Hamilton, Ontario which includes a new church. The lead architect for the project is Emma Cubitt of Invizij Architects in Hamilton, Ontario.
Emma is a Principal of Invizij and specializes in housing, working with non-profits, and sustainable design. A graduate of both the University of Illinois and University of Waterloo, she is a registered architect with the OAA and has over 15 years of architectural experience. Emma’s passions – livable small spaces, affordable housing, cycling, and sustainability – have shaped her as a designer. Driven by values of justice and inclusion, Emma is involved in various community-building initiatives in downtown Hamilton, and is a proud advocate for laneway housing and Passive House design.
Tell me a bit about Invizij Architects. How did the firm come to know about Passive House?
Invizij was founded in 2012 from the roots of our predecessor firm, Garwood-Jones & Hanham. Our projects include a wide range of building types, from institutional buildings to recreation centres to multi-residential housing and places of worship. From the inception of the firm, there has been a focus on sustainability with good detailing of the building envelope.
One of our clients, a non-profit housing provider called Indwell, was interested in learning about a new way of building they had heard of called “Passive House.” This was back in 2016, and we’d already been designing lower energy buildings for many years. We were excited to learn the “Passive House way” and jumped right in, all taking training together (including Indwell, our contractor, mechanical and electrical engineers, and us, as the architects). Following our first Passive House project together, Indwell committed to designing to Passive House levels going forward, and we’ve been able to learn and grow with them (and many new clients) since.
Nearly all our designs incorporate the principles of Passive House, even when not attempting certification., More than half of our work is to Passive House levels. We currently have 15 Passive House projects that are under construction or completed, and many more than that in various design phases.
Would you say, then, that Passive House is exponentially growing within the business?
For our firm? Definitely. Almost all those projects have been in the housing sector, such as multi-residential buildings. Most of the clients have been non-profits and they’ve been able to access additional funds through CMHC and other programs. So that’s been really rewarding. Some of our other clients are for-profit developers that have a forward-thinking mentality for low-carbon buildings that they want to create.
Tell me about the 500 James Street North project.
it was a unique, rather large mixed-use project. We had two clients for the project: one was the church, now called James North Baptist, and the other was Indwell, an affordable housing developer. The church owned the building, so they were technically our client, but we worked closely with both organizations.
We started in 2016 and it was completed in the middle of 2020 during the pandemic, so timelines were slowed near the end. Previously, this site was a commercial plaza. Initially, the church had bought the site and they intended to redevelop the existing brick building for the church. In fact, they had already gone to building permit when this partnership with Indwell came about.
As previously mentioned, Indwell committed to Passive House back in 2016. When they started these discussions with the church about working on a project together, they said, “It would need to be Passive House, because that’s just what we do now.”
And the church said, “What’s that?”
The result was one of the larger mixed-use Passive House projects in Canada at the time. The church area is half the GFA — about 30,000 square feet, designed for 500 seats. The rest of the building is 45 apartments: a mix of one and two bedrooms.
What are some of the unique design properties of the building?
The church wanted a design that fit into the neighbourhood and its near-waterfront setting. It was important to them to have brick cladding. but that wasn’t very common in Passive House projects, which tended to use lightweight cladding. We had to do research to figure out how to support the brick in a way that didn’t have too much thermal bridging.
Our clients pushed us on. We hadn’t seen brick done in a Canadian Passive House project, especially for multiple stories, but some projects in Europe have used a thin brick ( they shave off the outside surface of the brick so it’s only three quarters of an inch deep). We initially tried to use this thin brick product – because we thought it would be the best option – but it’s not very common here, and it wasn’t working out.
Instead, we went to the typical masonry world and found a system of masonry support clips called “Fero Fast.” We then used one of the thermal breaks that we had used in other parts of the building, “Armatherm,” so that the brick ledges would be supported in a thermally broken way. We also specified a Z girt from the States called “Green Girt,” that is made of fiberglass and used that to support the panelized cladding as well as the brick ties. After putting these new materials accurately into the energy model generated for the project, we saw that it didn’t cause that much derating. Since then, we’ve worked on a few other Passive House projects that have brick and further refined our detailing.
On mid-rise projects, we’ve now moved to a hybrid wall system composed of wood studs with insulation provided both in between the studs and on the outside of the stud wall; but for this project it was all on the outside of the structure (as the structure type had to be non-combustible due to the mixed-use nature of the building). I would say that it’s not that common yet to design to Passive House standards with a non-combustible building. It made for some different detailing decisions for this building.
One of the important things for the church was having lots of natural light in the gym, because it was also going to act as a sanctuary. We couldn’t use standard skylights, as they wouldn’t be able to thermally perform well enough, and we couldn’t afford the huge cost of Passive House skylights, so we used a product called Kalwall, which is an insulated translucent panel. We worked with the manufacturer to provide some huge expanses of this kind of daylighting product, and that was a real success. There’s a big ‘skylight’ in the gym to let light in, and another one in the atrium, between the church space and where they have the cafe and other spaces.
As your long-term Passive House building client, does Indwell find the building costs on par with any other construction build, or are they still a little bit more? Or have costs it been going down with each project?
It’s very hard to tell exactly, but we can very confidently say we can build to Passive House standards with about a 5% premium or less now. On our first project, we had NRCan do a study and had separate cost consultants comparing what we had designed to a “code build,” and they quoted 4% premium, which was helpful.
Are there any challenges or learning curves from this project that you feel others in the Passive House community might learn from?
We didn’t do the energy model, but I know that it was more challenging than usual for our energy modeler, Peel Passive House, because they had to put two separate models together and merge them because one was needed to capture the church use and the other to capture the housing use. I know that was tricky and I don’t know if there’s easier way to do that now.
We also learned that getting the form right at the beginning of a project is a big deal. We had a few renditions of different massing, until we found one that we felt would be able to meet the Passive House criteria. We kept the building more compact than earlier versions.
At one point, we were going to have a cantilever over the parking access; however, that would have created a lot more building envelope, so we decided to move that extra space into the basement, instead. I think making those smart decisions up front, using different 3D modeling tools, helped to make it easier to meet the Passive House requirements later on.
For this project, and for many others, we’ve worked with a great contractor, Schilthuis Construction, as a partner. They have probably built ten Passive House projects at this point. We’ve learned together, and that’s really made it easier to know that you have a contractor which will have no problem meeting the air tightness targets or paying the required attention to detail regarding thermal bridging during construction.
Architects: Invizij Architects
Energy Modelling: Peel Passive House
Contractor: Schilthuis Construction