A clear guide for homeowners, architects, and general contractors navigating municipal inspections and engineering approvals in the GTA.
These rules apply to every custom stair and glass guard system we design across Toronto and the GTA.
OBC Part 9 requires that open risers block the passage of a 100mm sphere to prevent a child from falling through. We achieve this with solid steel riser bars, glass infill panels, or extended hardwood tread lips that close the gap while preserving the floating aesthetic.
Interior stair guards must be at least 900mm high; landing and mezzanine guards must be at least 1070mm. Frameless glass or metal guards must resist the required concentrated and uniform loads. All glass is CAN/CGSB 12.1-2017 certified tempered or laminated safety glass.
Toronto, Mississauga, Vaughan, and York Region building departments require stamped P.Eng drawings for concealed steel stringers, floating supports, and cantilever mounts. Our Ontario-licensed engineer provides load calculations, connection details, and sealed shop drawings for permit submission.
OBC limits maximum riser height, minimum tread depth, and maximum variation between adjacent rises. Treads must be slip-resistant and handrails must be continuous, graspable, and terminated correctly at walls or newel posts to pass final inspection.
Our process aligns with municipal inspection schedules so your project stays on track.
We review your floor plans, opening dimensions, and finishes, then model the stair in 3D CAD and calculate live loads, dead loads, and connection reactions.
Our Ontario P.Eng seals the structural drawings. We prepare the permit package and submit it to your municipality, or provide it directly to your contractor for submission.
Before drywall, the concealed steel plates, mono stringer base, or cantilever pockets are installed and inspected to confirm they match the stamped drawings.
After finishes, we install treads, guards, and handrails. The municipal inspector verifies guard heights, sphere rule compliance, and structural connections before occupancy approval.
Yes, provided the existing structure can support the new steel stringer or cantilever mounting and the design meets OBC Part 9 dimensional and guard requirements. A site visit and structural assessment are always the first step.
Frameless glass guards can be designed without a top cap, but they must still meet height and point-load requirements. A separate, continuous graspable handrail is required on at least one side of most stair runs.
If the open riser gap exceeds the 100mm sphere rule, the inspector will require a remedial fix before occupancy. We design every open riser with compliant riser bars or tread lips from the start to avoid this scenario.
Disclaimer: This guide is provided for educational purposes based on OBC Part 9 standard guidelines. All custom installations require project-specific P.Eng verification and municipal approval. Always consult a licensed Ontario engineer and your local building department before construction.
Speak with an engineering specialist about your drawings, permit package, or inspection timeline.
Speak with an Engineering SpecialistAttach floor plans or describe your municipal inspection challenge. We reply within one business day.
Attach drawings or permit details.
Need code guidance by phone?
(416) 839-8416