Going for Zero: OAA Headquarters Retrofit, Toronto, Ontario
PROJECT Ontario Association of Architects Headquarters Retrofit, Toronto, Ontario
ARCHITECT David Fujiwara Architect (retrofit), Ruth Cawker Architect (1991 original building)
TEXT Kathleen Kurtin
This May, the Ontario Association of Architects (OAA) officially reopens its doors to the public and its members after completing the renovation of its headquarters in Toronto. The net-zero targeted project embodies a commitment to demonstrate first-hand how existing buildings can be adapted rather than replaced, as the profession strives towards climate stability.
The OAA has a history of proactive environmental responsibility. When the headquarters was designed by Ruth Cawker, winner of the 1989 province-wide design competition, it was built to the R2000 standard—the environmental high bar of the day. The project anticipated the future, with its proposal for rooftop solar panels that would act as louvres. Thirty years later, that final piece has become a visible reality. As a whole, the building stands as an example of the profession’s environmental responsibility to members and guests as well as the neighbours and motorists passing by.
The Road to Renewal
After serving the Association and its members well for more than 25 years, the OAA Headquarters required extensive maintenance. Additionally, there was a space crunch, as staff had grown to support a steadily increasing membership.
In 2015, the OAA faced the decision of whether to renovate its headquarters or find a new home. The OAA Council ultimately decided that the financial impact of moving from a landmark building and the OAA’s largest economic asset—combined with the environmental impact of discarding the embedded carbon in the existing building—was not in the best interests of the membership or the public. Further, there was an opportunity to be realized by updating the current building: it could demonstrate how, through renovation and updating, architects could be leaders in reducing the environmental burden of unnecessary demolition and new construction.
Once cutting-edge, the building’s mechanical system was now outdated and approaching the end of its life cycle. This meant energy consumption was significantly higher than in new low-rise office buildings of the same type. After much research, the OAA found that net-zero carbon emissions could be achieved through a deep energy retrofit that reduced consumption, the installation of a geothermal system, and the addition of photovoltaic systems to offset remaining energy use.
Environmental concerns had escalated over the building’s life, and technologies had evolved. In 2009, the Association committed to the 2030 Challenge, which aims to take the building sector to zero carbon emissions by setting performance targets for all new buildings and major renovations. For this initiative, rather than meet the 70 percent rate projected for 2020, the OAA chose to take a leadership position and set a target of 100 percent. The plan was to meet the 2030 Challenge a decade early.
As both the owner and the occupant, the OAA understood that investing in the building would reduce future operating costs and provide a simple payback (somewhere between seven and 20 years, depending on energy costs). The result would also serve as a strong case-study for architects to use in their own work and outreach to clients. The carbon neutral renovation would have educational value for members, the general public, and students.
The New Building Systems
The OAA Building Committee, led by architect Sheena Sharp, worked with multiple consultants for more than three years to research various options, looking for a “sweet spot” that would balance operating and embedded carbon ambitions.
The final result was coordinated by David Fujiwara Architect and focuses on three areas of intervention:
• completely rethinking the mechanical systems;
• intensifying and transforming the office and meeting room environment, prioritizing transparency and openness; and
• reusing the existing carbon footprint of the building wherever possible.
Reaching the goal of net zero meant eliminating the use of fossil fuels and offsetting any electricity consumed. This was achieved through installing a geothermal system and three types of solar panels, as well as reducing energy consumption.
The geothermal heating and cooling uses a closed-loop ground-source exchange system, composed of a double circular field of 15 wells that are more than 180 metres deep. As Toronto’s climate requires more heating than cooling, the field is balanced using warm water from solar hot water panels on the roof.
In addition to the solar hot water panels, two types of photovoltaic (PV) solar panels were installed on the existing roof armature. This includes more than 400 square metres of PV panels by Heliene, as well as about 200 square meters of an innovative system by Morgan Solar, combining translucent and PV panels. The Morgan Solar system forms a semi-transparent canopy over the outdoor terrace on the south façade, and includes an integrated LED array for special events and detail lighting.
Electrical production from the rooftop PV panels—100,000 kWh annually—is returned to the grid, offsetting the power used to operate the building. The goal is to be electrically power-balanced over the course of the year, thereby achieving net zero energy.
At the same time, the building’s base level energy consumption is reduced through enhanced installation, triple-glazed View electrochromic glazing, right-sized fans and pumps, and high-efficiency LED occupancy-activated lighting.
Daylight is the primary source of light throughout, working in conjunction with dynamic glass that automatically adjusts to sunlight, providing ideal levels with minimal glare. A 3M daylight-redirecting film added to the transom windows deflects exterior light towards the ceiling, so that it bounces deeper into the building.
Windows can be responsible for up to 40 percent of a building’s total heating and cooling energy consumption. Compared to traditional low-emissivity (low-e) glazing, the OAA Headquarters’ combination of View dynamic glass, triple-glazing, low-e film (double low-e at transom windows) and the daylight redirecting film is expected to reduce the building’s peak energy load by approximately 20 percent.
Thermal bridging has been reduced by adding insulation to soffits, solid exterior walls, and walls under windows that were opened during the renovation. The R-values of the completed walls vary from the existing R-10 to a new R-30 level where possible.
Critical to the success of the project is maintaining the airtightness of the existing building. Unlike many other buildings constructed in the early 1990s, the OAA Headquarters was very airtight right from the beginning, as verified by a preconstruction blower door test. The renovation work required penetration of the existing envelope in some locations, and the contractor has been challenged in resealing the building to its previous levels. The team continues to make adjustments with the goal of meeting and exceeding the standard set by the original building. This will need to be confirmed by a subsequent blower door test.
The transition from office to open-plan collaborative space allowed for greater use of natural light, and for the reduction of mechanical infrastructure—including fans, which are heavy consumers of electricity.
With its new interior layout, the OAA Headquarters doubles its capacity without increasing its footprint.
Having steadily grown over the last 25 years, the OAA staff of 33 now supports more than 35 member committees, dedicated to improving practice, protecting the public, promoting design excellence, and increasing awareness. The Association also supports students and intern architects, as well as regulating complaints and discipline. The layout of the building was updated to optimize the use of space, including adding moveable walls that increase flexibility in the meeting rooms.
A two-storey atrium and terrace were integral to the original design of the building. The previously underused atrium has been transformed into a café space for staff and members, and doubles as the building’s air displacement system.
The top level surrounding the atrium is devoted to staff work and collaboration areas. Glass walls in atrium-facing collaborative spaces maintain the open, transparent qualities of the original design. The lower level of meeting and conference rooms has been enhanced to today’s standards.
As an employer, the OAA strives to provide an inclusive, safe and healthy workplace that is accessible to all. The staff area has been updated and includes personal workspaces with convertible sitting/standing desks. A variety of open and enclosed collaborative workspaces—in the very high ratio of one collaborative space per four staff—allows for flexibility in types of work and levels of privacy. A robust wireless network and digital phone system allow staff to move freely throughout the building.
The intensification of use in the existing building was critical for controlling the embedded carbon footprint. Existing seating was reused and refurbished when necessary, while new furniture was produced locally by Toronto-based Global Furniture, helping to minimize its embedded carbon footprint.
All meeting rooms are outfitted with video conferencing capabilities, allowing members and volunteers from across Ontario to participate on Committees without having to travel, increasing accessibility for the membership and further reducing the organization’s environmental footprint.
All systems in the OAA Headquarters are continuing to be adjusted during commissioning and with seasonal changes. The National Research Council (NRC) is monitoring the building, and Siemens will also be tracking the systems to help ensure the building meets its 2030 Challenge targets. This information will be shared with the profession, the wider building industry, and the general public as “lessons learned,” demonstrating some ways to address the retrofit of Ontario’s existing building stock.
The month of May will mark the kickoff of a public awareness program around the building, including participation in the 2020 Toronto Doors Open program and an official opening celebration during the OAA Annual Conference. Elementary and secondary school students will be invited to tour the building.
The OAA Headquarters is more than offices and meetings spaces—it is also the public and physical embodiment of architects’ skills and aspirations for the community. The OAA continues to talk about the leadership role architects must play—but its Headquarters speaks even more powerfully, by demonstrating first-hand how existing buildings must be addressed to minimize environmental impacts, improve resiliency, and help ensure a sustainable future.
Kathleen Kurtin, OAA, FRAIC, is the president of the Ontario Association of Architects.
CLIENT Ontario Association of Architects | ARCHITECT David Fujiwara Architect | CONTRACTOR MJ Dixon Construction | MECHANICAL/ELECTRICAL WSP Canada | STRUCTURAL Peter Sheffield & Associates | LIGHTING Gottesman and Associates | INTERIOR LAYOUT CONCEPT Interior Architects | QUANTITY SURVEYOR Turner Townsend | CFO MODELLING WSP Canada, EH Price Industries, Prof. Bernier/Ecole Polytechnic, Transsolar KlimaEngineering | CIVIL Planmac Engineering | DESIGN CHALLENGE National Research Council and Greg Allen, P.Eng. | COMMISSIONING WSP Canada | OAA BUILDING COMMITTEE Kathleen Kurtin, Gord Erskine, Sheena Sharp, Andy Thomson | BUDGET $8.5 M | OCCUPANCY Summer 2019
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