What permits do i need to convert a single-family home into a duplex in Saint John under the new housing rules?

Converting a single-family home to a duplex in Saint John requires multiple permits and approvals, but the city has been working to streamline secondary suite approvals under recent housing initiatives.

You'll need to start with the City of Saint John's Growth & Community Services department at (506) 658-2835 to confirm your property's zoning allows duplex conversion. Saint John's zoning varies significantly by neighbourhood — some residential zones permit duplexes by right, others require rezoning or development variances. The city has been updating zoning bylaws to encourage gentle densification, but you must verify your specific property's status before proceeding.

Building permits are mandatory for the conversion work itself. The structural modifications, fire separation between units, and code upgrades will require plans prepared by a professional (architect or engineer for complex changes). Each unit needs separate entrances, proper egress windows in bedrooms, and 45-minute fire-rated separation between units per the National Building Code 2020 (effective May 1, 2025 for new applications in NB). You'll also need to upgrade electrical service if the existing panel can't handle two units.

All electrical work requires permits from NB Power (1-800-615-0522) and must be done by a TIS-licensed electrician. The plumbing modifications — separate water meters, additional bathrooms, kitchen hookups — require TIS plumbing permits and licensed plumber installation. If you're adding gas appliances, that requires separate TIS gas permits and licensed gas fitter work.

Development charges and utility connections can add significant costs. Saint John Water requires separate water meters for duplex units, and you may need service upgrades. The conversion typically costs $40,000-$80,000 depending on the home's age and required modifications — older Saint John homes (common Victorian/Edwardian stock in the South End) often need extensive electrical and plumbing upgrades.

Contact Saint John's planning department first to understand your property's specific requirements — the recent provincial housing legislation has pushed municipalities to be more flexible, but local zoning still governs what's permitted where.