Designing Small Multi-Unit Residential Buildings

Small multi-unit residential projects occupy an increasingly important role in Ontario housing delivery, supporting missing-middle housing, intensification strategies, adaptive reuse projects, and gentle density initiatives. While these projects may fall within the scope of small building provisions under the Ontario Building Code, their design often presents practical challenges involving life safety, fire separation, exiting, accessibility, existing building constraints, and coordination with municipal approval requirements.

This session examines the design of small multi-unit residential buildings containing three or more dwelling units within Ontario practice. The webinar explores both existing residential buildings undergoing conversion or renovation and new construction projects designed under small building provisions. Participants will gain practical insight into how code requirements, existing conditions, and design objectives interact across different project scenarios, and how architects can navigate common technical and regulatory challenges.

Key Topics Discussed:

• Change-of-use and adaptive reuse considerations in existing buildings
• Code compliance triggers for older residential structures
• Fire separation and life safety requirements
• Means of egress and exiting design challenges
• Structural limitations in existing building conversions
• Accessibility upgrades and barrier-free design requirements
• Renovation versus new construction decision-making
• Municipal approvals and permitting coordination
• Small building classification under the Ontario Building Code
• Multi-unit residential layout and spatial planning strategies
• Fire protection and compartmentation design principles
• Building envelope and energy performance considerations
• Coordination between architectural and engineering disciplines
• Documentation and submission requirements for approvals
• Common design and compliance pitfalls in small residential projects
• Missing middle housing and gentle density implications
• Constructability, cost constraints, and project delivery challenges
• Lessons learned from Ontario residential developments