WINNER OF THE 2025 RAIC RESEARCH & INNOVATION IN ARCHITECTURE AWARD As one of ten test cases for their research, LGA Architectural Partners submitted a building permit application and alternative solution 
to the City of Toronto for a three-storey small apartment building proposed to be constructed with a single exit stair and an elevator opening into the exit. ARCHITECT  LGA Architectural Partners The Single Exit Stair Building Code research project explores innovative alternatives to the Canadian building code requirement for two exit stairs in multiplexes and small apartment buildings. Through pilot projects, prototypes, and extensive review of local and international building codes, research led by LGA Architectural Partners demonstrates that single-stair alternative solutions (SSASs) increase the feasibility, affordability, accessibility, sustainability, and design flexibility of missing middle housing, while achieving the safety objectives of the building code. By advocating to remove barriers to missing middle housing, the research advances the goals of the National Housing Strategy, the CMHC Housing Accelerator Fund, and newly adopted zoning laws that encourage construction of such buildings in urban areas across Canada. Over the last four years, the project has evolved greatly in scope. Building upon the foundational research and findings of then-McGill student Conrad Speckert’s graduate thesis (secondegress.ca), the work has shifted from ideation to real-world implementation. LGA designed six prototypes for single exit stair building designs at three, four and six storeys in height, using typical residential lot sizes across Canada. To ground the research, LGA designed six prototypes for single exit stair building design at three, four and six storeys in height, using typical residential lot sizes across Canada. Each small apartment building design includes a comparison with prescriptive egress requirements as a measure of floor area efficiency, construction cost, and rental income. The prototypes illustrate the architectural aspects of single exit stair building design as it relates to relevant requirements within Part 3 and Part 9 of the National Building Code. The purpose of the prototypes is also to demonstrate the relatively small scale of such buildings, and to help inform cost/benefit and fire safety analyses. Some key takeaways from the development of the prototypes include noting that the implementation of SSASs in small apartment buildings enables more bedrooms, more access to daylight and fresh air, and more accessible suites within the same height and area. Providing upgraded life safety systems like an automatic sprinkler system, smoke-sealed doors and advanced fire alarms makes a three-storey building with a single exit stair comparatively safer than a same-size building with two exit stairs designed to the prescriptive code. Moreover, SSASs make it easier for small-scale buildings, such as multiplexes, to integrate accessibility features like elevators, in circumstances where stacked townhouses would otherwise be constructed. Each of LGA’s six prototype designs includes a comparison with prescriptive egress requirements as a measure of floor area efficiency, construction cost, and rental income. Another significant portion of the research project involved developing a series of single stair pilot projects to test the approvals process across the country. LGA collaborated with nine other architects and building code consultants across Canada to develop site-specific single stair alternative solutions. Each team scaled, replicated, and adapted the concept for different types of multi-unit residential buildings, ranging from three to six storeys in height, and submitted designs to local authorities for review. Each proposal included additional fire and life safety measures to meet the same level of performance and acceptable risk as the minimum prescriptive requirements for buildings of the same height and classification. Arguably, the project’s largest impact has come from industry-focused education and knowledge sharing. Through dissemination of SSAS research at numerous presentations, conferences, and panel discussions nationwide, LGA has contributed to a better understanding of Canada’s objective-based building code, and encouraged the careful use of innovative design strategies to increase housing supply. The impact of this research and knowledge sharing has already been felt. Transformative policy changes and building code amendments have been initiated across Canada. In April 2022, LGA and David Hine Engineering submitted a request to the Canadian Board for Harmonized Construction Codes (CBHCC) to introduce single exit permissions for up to three and six storeys. This work was funded by a CMHC-SSHRC Balanced Supply of Housing grant. The proposal has been analyzed by CBHCC, and the topic has been prioritized for the 2025-2030 code cycle of the National Building Code of Canada.  Meanwhile, in British Columbia, a building code update was approved in August 2024, allowing small-scale multi-unit housing of up to six storeys to be constructed with a single exit stair. Other provinces such as Alberta and Ontario, as well as officials at the City of Edmonton and City of Toronto, have prepared feasibility studies and expressed an interest in potential code reform. The next five years is anticipated to see significant use of single stair alternative solutions, until prescriptive regulatory dependencies are updated across Canada. The lessons learned from the pilot projects, prototypes and related research also indirectly support the code development process. This trajectory is similar to the recent adoption process for mass timber across Canada, beginning with performance-based alternative solutions that informed corresponding building code changes. Jury Comment :: This meticulous study of single exit stair building code reform presents a transformative approach to addressing Canada’s housing challenges. Through richly documented research and elegant visual presentation, the project demonstrates a comprehensive understanding of current barriers to housing supply. Working at the system level, this initiative promises far-reaching impacts on missing middle housing morphology across Canada. The thorough analysis and detailed solutions position this work to meaningfully influence future building codes. To learn more about this project, visit www.singlestair.ca.  The jury for this award included Jessie Andjelic, Chris Cornelius, Camille Mitchell (FRAIC), Maya Przybylski, and Terrence Smith-Lamothe (MRAIC). PROJECT TEAM AND COLLABORATORS LGA Architectural Partners, Haeccity Studio Architecture, AIR studio, Kelvin Hamilton Architecture, 5468796 architecture, Invizij Architects, SvN Architects + Planners, mcCallumSather, Office Ou, Lateral Office, Ha/f Climate Design, GHL Consultants, Celerity Engineering, LMDG Building Code Consultants, Vortex Fire Consulting, David Hine Engineering, NSP Consultant, Vermeulens, Urban Formation, City of Edmonton, Vancouver Urbanarium As appeared in the May 2025 issue of Canadian Architect magazine The post 2025 RAIC Awards: Single Exit Stair Building Code Reform appeared first on Canadian Architect.