Largest Passive House Retrofit in Canada
This landmark hotel, banquet hall, and rooming house complex was originally built in the 1960’s. It has now been converted to 57 affordable apartments, with ground floor commercial space for a convenience store, pharmacy, and restaurant. The entire building has a GFA of 45,000 ft² - making it currently the largest passive house retrofit in Canada.
History
The first building on the site was a late 1800s farmhouse, which later evolved into a rural crossroads rooming house in the early days of automobile transportation. A three-storey addition was built in the 1960s, followed by larger extensions in the ‘70s and ‘80s as George & Mary’s Tavern and Banquet Hall boomed. Fires in the ‘90s and a general decline in the business led to the property being sold to Indwell in 2016.
Renovations
Indwell's intention was to renovate and create much-needed affordable apartments. Invizij Architects developed a plan that involved demolishing 40% of the building that was structurally unsound due to fires, keeping the largest existing portion with its open-web steel joists and load-bearing exterior walls. The demolished area was reconstructed with steel stud and precast concrete floors on the same footprint, but aligned floor heights for barrier-free accessibility.
Meet the Team
Emma Cubitt is an award-winning Hamilton-based architect and Associate at Invizij Architects. Her passions are affordable housing and sustainability, which helped guide this project’s trajectory. Graham Cubitt is the Director of Projects and Development at Indwell, a Hamilton-based charity that has recently developed over 400 units of affordable housing with supports for individuals seeking health, wellness & belonging in southern Ontario. The teams responsible for the project have since worked on several more passive house projects together. Graham kindly gave an informative tour of the building on August 1st 2018, describing the project and the learning curve it took to make it happen.
Architect: Invizij Architects
Mechanical/Electrical Engineer: CK Engineering
PH Consultant: Peel Passive House
Structural Engineer: Kalos Engineering
Construction Manager: Schilthuis Construction
Airtightness Contractor: Fourth Pig Green & Natural Construction
Airtightness Testing: WSP
Air-tightness Targets
During project’s planning phase, the development team was just learning about the Passive House design standards. Indwell committed to pursuing the EnerPHit standard for the project, and Invizij marshaled an experienced team of designers and constructors who were all willing to approach the steep learning curve together. Potential challenges they foresaw included sizing the HVAC system appropriately, achieving air-tightness targets on a complex building envelope retrofit, and ensuring adequate insulation rates given the tight site setbacks of the existing building. In the end, the team’s commitment to working through problems together allowed them to resolve all the constructability issues; indeed, the first blower door test was amazingly low at 0.30 and the final test achieved 0.31 ACH @ 50Pa - 30% of what was allowed by EnerPHit standards! The team's take-away learning was that with good detailing, it is not too challenging to meet PH air-tightness targets with a larger building.
Airtight!
This was the first project Schilthuis Construction had worked on that attempted such ambitious air tightness, so they worked with Fourth Pig Green & Natural Construction to ensure close attention was paid to the building envelope’s construction. That attention to detail paid off, with the building achieving an impressive 0.31 ACH on final testing, while the EnerPHit standard requires 1.0ACH @ 50Pa.
Construction
Given the multiple existing wall types, the team determined to wrap the entire envelope with Blueskin air/vapor barrier, use Cascadia fiberglass clips to support the cladding, then apply polyurethane insulation in three lifts creating an effective R-value of +R36. Spray foam was specified due to its high u-value/inch, allowing the exterior insulation approach while not encroaching on the tight property lines. The team decided to use a new spray foam on the market called Insulthane Extreme by Elastochem. Made locally in Brantford, it has a global warming potential of 1 (same as CO2), whereas other spray foam blower agents can have global warming potentials of 1000+. This was important to Indwell as it sought to minimize the environmental impacts of the project.
Window Detail
An early design decision was to enlarge all the existing window openings by over 50% to provide ample daylighting and views for each studio apartment. Achieving the PH standards for performance led to choosing certified windows by Klearwall from Ireland. Invizij closely detailed the windows to ensure performance, using a fibreglass angle to optimally align the windows in the insulation layer.
Outdoor Amenity Space
A second-floor outdoor terrace was designed with benches, a canvas awning, and community vegetable gardens. The adjacent windows will achieve privacy with window shades provided by Indwell and planter boxes with tall grasses. In addition, the low-e coating on the windows provide privacy due to its light reflective properties. This outdoor space was needed to encourage health and well being for tenants, as the overall site was already deficient in amenity areas.
“Research has demonstrated that inequitable access to green space can relate to health disparities or inequalities. Our goal was to create integrated green space in the project to provide greater health and well-being for the tenants, while also providing a safe space to relax with neighbours rather than just hanging out on the sidewalk.” - Emma Cubitt
A second-floor outdoor terrace was designed with benches, a canvas awning, and community vegetable gardens. The adjacent windows will achieve privacy with window shades provided by Indwell and planter boxes with tall grasses. In addition, the low-e coating on the windows provide privacy due to its light reflective properties. This outdoor space was needed to encourage health and well being for tenants, as the overall site was already deficient in amenity areas.
“Research has demonstrated that inequitable access to green space can relate to health disparities or inequalities. Our goal was to create integrated green space in the project to provide greater health and well-being for the tenants, while also providing a safe space to relax with neighbours rather than just hanging out on the sidewalk.” - Emma Cubitt
Studio Apartments
The project’s 57 apartments include 55 studios and two one-bedroom units, that all come furnished to make it easier for tenants with very low incomes to move in. The apartments are a modest size according to Passive House International Standards - the average unit size is 260 ft2, with construction cost of $205/ft2. One of Indwell’s main drivers for choosing the PH approach was to minimize tenant operating expenses. The energy modelling suggests it will cost just $40/year for tenants to heat their apartments. This is an important part of enabling tenants to afford their housing with just $500/month available for rent.
“We knew this first PH project would be a huge learning curve for our whole team, so we did our best on each decision to maximize compliance with the EnerPHit standards, while still meeting our deadlines for delivering the completed project. Through this process, we’ve realized the importance of the building envelope, eliminating thermal bridging, and how to research and find efficient and feasible systems. In the year since we started construction, more PH-certified products are available in Canada, so it will be easier to make smart design choices on future projects to reduce our environmental impacts as we grow.”
- Graham Cubitt
Temperature Comfort
The building has been designed to not overheat in the summer and to stay warm in the winter. All heating and cooling is generated from a makeup air system providing a constant 35 cfm of conditioned air into the units. On the coldest winter days, any supplemental heating required will be provided by a 500w electric heater in each unit. The building is big enough to hold embodied energy and thermal mass, with airtight construction and triple pane windows - the tenants shouldn’t need extra heating! Ceiling fans are included in each unit as well, providing destratification in winter and improving perceived cooling in summer. In addition, 30" deep sun shades on the south, east, and west facades will assist with keeping the sun out of windows in the summer, while allowing the lower winter sun in. This approach to thermal comfort was possible because of the modest unit sizes, and helped reduce equipment capital costs and complexity while providing higher efficiency system that’s functional throughout the year.
Walk in Cooler
Indwell determined that the building’s benefits needed to extend beyond their tenants, so the initially planned community room with a kitchen was expanded to become a community restaurant and neighbourhood food hub. It offers a culinary academy for job skills training and lower-cost meals to the economically challenged neighbourhood, along with meeting rooms and other amenities for community groups.
The retrofit project’s energy goals were made more complicated by including a variety of energy-heavy equipment in this mixed-use program. The convenience store and restaurant both have large walk-in coolers and other refrigeration units. The restaurant also has full-scale exhaust hoods over gas-fired cooking equipment and high-temperature dishwashing equipment. While every effort was made to reduce energy loads, and the building envelope and airtightness goals were easily met for EnerPHit targets, the overall Primary Energy Renewable (PER) was exceeded due to the number of suites / building area and energy loads of the commercial equipment.
Mechanical Room
Although this project is within all other targets for certification, it was determined early on that they would not pursue the standard due to PER requirements. As such, the option to use some locally familiar products and materials was pursued over importing PH-certified equipment. High-efficiency Canadian-made HRVs from Engineered Air were specified, providing the apartments with virtually all heating and cooling needed through the ventilation air supply. Lochinvar high-efficiency boilers supply the commercial spaces with heating, as well as the domestic hot water for the building. The entire building features LED lighting.
Operation
Indwell’s funding agreements require them to guarantee rental affordability for 30+ years, so long-term operating costs were a key driver in decision making. This benefits tenants directly - most of whom receive a fixed, low income - in terms of utility costs. But it also has benefits for Indwell in terms of future-proofing the building. Graham explains, “We will own and operate this building for the next 50 years, so we want to be ready should regulations change on cutting GHG emissions, energy sources, or requiring air conditioning. With the very efficient PH building, we won’t be impacted by needing to do costly retrofits later. This means that our tenants and the environment benefit immediately, rather than waiting until 2050 or some future date to see improvements.”
New Life
This affordable housing retrofit is giving new life to crossroads previously known for its dilapidated condition and various types of vice. The new structure, now known as Parkdale Landing, will no longer be the home-of-last-resort, but instead provide tenants with a new start, as many will have will have experienced homelessness, prolonged hospitalization, or incarceration. While tenants have full-fledged apartments with kitchens, basic needs like nutrition can be supported by purchasing a daily meal through the food hub. Tenants with weak credit often face challenges hooking up to utilities, so Indwell is sub-metering hydro to ensure every tenant can access core needs.
Liveable
“Affordable Housing” can sometimes carry a stigma about its quality, durability, or lack of attention to detail. Indwell’s approach runs counter to this; they want to create great buildings that everyone would want to live in. Indeed, the Cubitts lived in one of Indwell’s buildings for four years, getting a first-hand understanding of what’s critically important to creating multi-residential buildings that promote health, wellness, and belonging. In designing Parkdale Landing, Invizij tried to incorporate a number of design elements that enhance the living experience in the building - from generous natural lighting, colour choices both inside and out, and even how the millwork functions. The end result is a high-quality complex that already has a waiting list before it’s even fully occupied.
A Change in the Approach
Indwell reports that making these changes to how they are constructing has been challenging, but not onerous. “It’s not particularly harder, not really more money, it’s just a change in how you approach the design and construction process,” Graham explains. “When comparing a good quality build to a Passive House build, the extra costs are minimal; it turned out to be about 3% more on Parkdale Landing. But on our two other Passive House projects under construction right now, we’re seeing the tenders coming in on par with market prices.”
Lessons Learned
The cost of investing in the learning curve is one area Indwell, Invizij, and their team do acknowledge can be a barrier for many in the industry, whether developers, designers, or constructors. As such, they have been working hard to share their experience through tours, trade shows, conferences, and other avenues in order to lower the barriers for Passive House principles to become common in the industry. “We have been talking with architects and builders across Canada,” reports Emma, “sharing our drawings, Passive House design details, and research on products and techniques that others can use to save time and effort.”
Nearing completion
Graham and Emma’s presentation at Passive Building Canada’s event “High Performance Design Meets Boots on the Ground describes Indwell’s adoption of the Passive House design strategies and demonstrates the economic and environmental benefits of low-energy buildings. This 45,000 ft² building just received occupancy, and the 57 low-income tenants moving in before Christmas will hopefully find health, wellness, and belonging. While this was the first Passive House project for the Indwell and Invizij team, they have five more PH projects in development already. They hope that one day this better way of building will become the norm of construction across the industry.
“ We’re going to do this for all our future projects because it just doesn’t make sense to go backwards.” - Graham
Articles on the PBC website reflect the views of the author and not necessarily those of PBC.