Scaling up Passive House Design in Canada
Across Canada, provincial and municipal levels of government are also raising performance requirements and establishing roadmaps for reaching Net Zero energy and/or carbon performance goals similar to those mandated by the Passive House standard. Examples include the City of Toronto Zero Emissions Buildings Framework, City of Vancouver Zero Emissions Plan for New Buildings, the BC Step Code, Ontario’s cap and trade program, the National Energy Code for Buildings and Canada’s Build Smart Program. Collectively, these policies are laying the groundwork for the design of Passive House buildings beyond residential to new large-scale institutional, civic, and commercial projects in Canada.
Until now, most completed Passive House projects in Canada have been residential—the majority being single-family homes, and the largest being a six-storey apartment building in Vancouver. But that landscape is about to change, and Passive House is about to scale up dramatically. Perkins+Will is among those firms committed to help bring the country’s first generation of large-scale, complex civic, institutional, and commercial Passive House buildings to life. Now more than ever, the firm sees the importance of designing climate-resilient buildings with low carbon emission profiles for its clients. Buildings must be designed to withstand acute shocks, extreme weather events, power outages, and utility rate escalation, and Passive House offers a solution to address these issues.
In anticipation of this future, the Canadian offices of Perkins + Will are investing in Passive House training for its next generation of designers. This consists of a seven day training course, held in house in the Perkins+Will offices with instructors from Passive House Canada. To be certified as a Certified Passive House Designer the candidates must sit a stringent 3-hour exam or alternatively be the main designer on a Passive House project that is certified. There are currently 17 CPHDs in Vancouver, 7 in Toronto and 1 in Ottawa. Eight of those Certified Passive House Designers share their insights on their recent training and how they think Passive House design will shape the future.
“The design fundamentals of Passive House mimic those of good building science. It asks the architect to once again be an exterior envelope expert, equipped with techniques and strategies to design an airtight and energy efficient building. Whether a project is going for Passive House certification or not, the design strategies learned through our training can be applied. For example, we are currently designing the Timmins Aquatic Centre to be ‘passive house inspired’. The project won’t achieve Passive House certification standards, however, passive house strategies such as a low glazing to wall ratio, increased insulation, and triple glazed windows are being employed, improving the building’s energy efficiency. Both the senior leadership and more junior staff are excited to apply Passive House principles to all our projects, helping us develop a stronger portfolio of sustainable and efficient buildings across the entire practice.
“What I really like about Passive House is that it takes a conservation approach to sustainability, which is more realistic and fundamentally more sustainable. It also pairs really well with Net Zero. A Passive House approach can get your energy consumption down to 10 to 20 percent of that of a conventional building, and if you consume less you need to generate less. So you can build a typical building and then buy thousands of solar panels to cover it, or you can invest in a higher-quality building and drastically reduce the consumption you need to offset with renewables. Passive House takes a conservation approach to sustainability, which is more realistic and fundamentally more sustainable. And because it focuses on reduction, rather than alternative or clean energy sources, it also pairs really well with a true Net Zero Energy approach. Passive House strategies can reduce a conventional building’s energy consumption by 80 to 90%, and the less you consume, the less you need to generate. So you can build a typical building and then buy thousands of solar panels to cover it, or you can invest in a higher-quality building and drastically reduce the amount of renewable energy needed to offset your consumption.
Passive House also pushes us to think more holistically about a project from day one. As a result, we engage with a larger set of consultants, like building scientists and engineers, right from the beginning instead of further along – a true integrated design process. Together we look at performance indicators such as engineering strategies, glazing ratios and projected energy consumption literally from day one.”
“Passive House training reinforces the need for integrated design early in the process: having all the design professionals, clients and contractors discussing building form, details, wall assemblies, mechanical layouts with a common goal. To create well-designed comfortable, healthy buildings with a minimal environmental footprint. This common goal means that there is a shared interest in solving even the trickiest of details or constraints. This integrated design approach means that there is more emphasis on upfront collaboration, meetings and design effort between design and construction disciplines. Achieving thermal bridge free design and hitting a stringent airtightness test requirements necessitate this. The informal discussions that evolve as part of the training are as much of benefit as the formal course material and set the course for this collaboration on future projects. The Passive House standard is strict in terms of performance requirements but not prescriptive, meaning that design teams can come up with innovative solutions based on local climate and methodologies. The principles learned are so fundamental we see the training as a benefit to all our projects, not just those targeting Passive House certification.
“Understanding the tools used to model, manipulate, and verify energy performance is a big part of becoming a Certified Passive House Designer. The impacts are extensive. Knowledge of the PHPP software enables the testing of built form and material assembly scenarios from the early stages of a project, while understanding thermal bridging calculations, air change flows and rates, and airtightness testing procedures add value throughout the design and construction phases. It is important to note that many of these skills are typically the domain of mechanical engineers, energy modellers and building science consultants. Passive House certification has increased my confidence in engaging issues concerning energy performance and indoor environment quality in my everyday work. While working on the design for Humber Centre for Technology Innovation, a higher education project targeting LEED Platinum, I was able to leverage my knowledge of Passive House concepts to develop detailing strategies that focused on thermal bridge reduction and airtightness. This helped us deliver an energy efficient design and will result in a healthier indoor environment for the client.”
“Passive House is a design mindset that informs the way you approach a project from the start. It makes you more conscious about building assemblies. The detailing techniques we learned for removing common thermal bridges and ensuring a continuous air-vapour barrier are also useful for meeting the energy use limits and indoor air quality stipulations set out by the Ontario Building Code and municipalities. Passive House energy-saving principles also provide an important stepping stone to even more aggressive energy targets, such as Net Zero.
The training also addressed some of the financial aspects of building to Passive House standards. Although Passive House buildings incur higher costs for highly insulated wall assemblies, high-performance glazing and frames, and more complex air-vapour barrier detailing, the upfront investment becomes offset by significant monthly savings on energy use. We also learned that for low- to average-performing buildings, taking measures to save energy is less expensive than taking measures to produce onsite renewable energy. As more municipalities mandate lower energy use and begin to promote Net Zero and carbon neutral projects, this distinction becomes important. Given the choice between producing a lot of energy to achieve Net Zero vs. designing the building to be passively more energy efficient, it makes more financial sense to put passive energy-saving strategies as the first priority
“When energy needs are very high, like in campus or office buildings, interventions like Passive House can have a dramatic impact on the environment. Perkins+Will has always been very conscious about the way their buildings operate and consume energy. Passive House now puts us in a good place to take our firm to the next step with clients. I feel lucky to have been part of this first group of training.
One of the challenges of Passive House design is going to be thinking about new ways to enclose buildings that require openness and transparency, while introducing more opacity.”
“Passive House changed my design approach from top-down only, to both bottom-up and top-down together. From an energy perspective, it pushes me to address details, such as envelope performance, airtightness, and thermal bridges, at an early design stage when ‘big picture’ assumptions are made. The passive house training explained the building science logic behind each dictated number, and convinced me that it is not a low energy myth but a down-to-earth approach to pursue energy efficient design in most, if not all, projects.”
“The really compelling thing about the Passive House standard is its simplicity. By focusing on first principles of building science, we can design comfortable, healthy, durable, low-maintenance, high performance buildings. In the past, some of these descriptors have been contradictory, if not mutually exclusive. Since having studied this approach several years ago, I have been unable to think about buildings without considering these first principles. There is a wide variety of factors and considerations affecting the design of a building, but regardless of the size, use, or budget of a project, Passive House will make it better. This is why Perkins+Will has developed an in-house training program to deliver the Passive House Design & Construction course to as many of our colleagues, consultants, contractors, and clients as possible.”