2024 Ontario Building Code Plumbing Requirements for Residential & Group B Occupancies
Sarah's Expert Insight
OBC Compliance Specialist
"When developing multi-residential units in London or seasonal employee housing in the Muskoka region, calculating exact occupancy loads early is critical to avoid layout revisions. At empcontracting.ca Inc. your construction contractor in London, Ontario, we ensure that these water closet ratios are integrated into the design phase to guarantee your project passes inspection without the need for costly plumbing retrofits."
Understanding the intricacies of the 2024 Ontario Building Code (OBC) is vital for ensuring your building project remains compliant and functional. At empcontracting.ca Inc. your construction contractor in London, Ontario, we specialize in interpreting these regulations to streamline your development process.
Section 3.7.4.4. Water Closets in Group B, Division 2 or 3 Occupancies
For care, treatment, or detention facilities, the OBC dictates a strict ratio of plumbing fixtures based on the number of occupants of each sex. This ensures adequate sanitation and accessibility in high-density or specialized care environments.
Minimum Number of Water Closets (Table 3.7.4.4.)
- Up to 9 Persons: 1 closet
- 10 to 24 Persons: 2 closets
- 25 to 49 Persons: 3 closets
- 50 to 74 Persons: 4 closets
- 75 to 100 Persons: 5 closets
- Over 100 Persons: 6 closets, plus 1 for every additional 30 persons.
Section 3.7.4.5. Mandatory Plumbing for Dwelling Units
In any dwelling unit where piped water is available, the OBC mandates the installation of four core fixtures to meet minimum health and safety standards:
- A kitchen sink
- A lavatory (bathroom sink)
- A water closet or drainless composting water closet
- A bathtub or shower stall
Section 3.7.4.6. Requirements for Residential Occupancies and Camps
Residential occupancies that do not qualify as standard dwelling units—such as boarding houses or student residences—must adhere to Table 3.7.4.6, which mirrors the scaling requirements found in Group B occupancies. However, specialized rules apply to seasonal or labor-focused housing.
Recreational and Worker Camps
For recreational camps (common in areas like Muskoka) and worker housing (often required for large-scale infrastructure projects), the code requires at least one water closet or privy for every 10 campers or employees of each sex. Additionally, these facilities must provide at least two lavatories for every water closet provided.
Disclaimer: This content is generated from the Ontario Building Code for educational purposes. Always consult with a licensed professional engineer or your local building department before starting any construction project in London, Ontario.