Grantham Ave | 02 Unit Conversion

St. Catharines

Property Type: Existing Single-Family Home with Finished Basement
Scope of Work: Legalization of 400 sq. ft. Basement into 1-Bedroom Secondary Unit

Project Overview:

Located in the heart of St. Catharines, this compact 400 sq. ft. finished basement already had the essentials—a kitchen, bathroom, and bedroom in place. Our team’s focus was to assess whether the existing conditions aligned with current Ontario Building Code requirements and, where they fell short, to propose strategic upgrades through Part 11 of the Code.

Using this renovation pathway, we were able to retain much of the existing layout while introducing only minimal improvements to bring the space into compliance. Key upgrades included adding a new egress window for legal bedroom escape and fire-rating the shared side stairwell used by the basement occupants. Shared laundry access with the upper unit was maintained, which is permitted under current regulations.

Scope & Strategy:

• Evaluated existing 400 sq. ft. basement for OBC compliance      using Part 11 for existing buildings

• Preserved much of the original layout: kitchen, bath, and      bedroom remained intact

• Upgraded life safety features, including:

  • New egress window in bedroom

  • Fire-rated separation along shared entry stairwell

• Confirmed ceiling heights, ventilation, and room sizes met      required standards

• Maintained shared laundry area with upper unit, as allowed by      code

• Focused on cost-effective solutions to legalize the space      without full gut-reno

Challenges Solved:

• Navigated legalizing pre-existing work with a focus on minimal      disruption

• Applied Part 11 provisions to reduce unnecessary demolition and      reconstruction

• Worked collaboratively with inspector to retain layout while      meeting safety standards

• Delivered efficient, low-cost legalization for a high-demand      rental unit

Investor Benefits:

• Spared significant renovation costs by leveraging Part 11      allowances

• Quickly brought unit into compliance with modest upgrades

• Increased monthly income with minimal investment

• Final unit remains functional and desirable, ideal for singles      or couples

• Located in a tenant-friendly market with growing rental demand      in St. Catharines

Current Status:

Permit approved. Construction completed. Unit is fully legalized and tenant-ready.