What are the rules for building a garden suite on my property in Moncton?

Garden suites (also called secondary dwelling units or ADUs) are permitted in most residential zones in Moncton under the city's updated zoning bylaw, but you'll need to meet specific requirements and obtain proper permits.

The City of Moncton allows secondary dwelling units in many residential zones, but the rules depend on your specific zoning designation and lot characteristics. You'll need to contact Moncton's Planning & Development department at (506) 856-4375 or info.plans@moncton.ca to confirm your property's zoning and get the current requirements, as these rules have evolved significantly in recent years.

Key requirements typically include:

• Minimum lot size (often 6,000+ square feet)


• Maximum size limits for the garden suite (usually 40-60% of the main dwelling's floor area)


• Setback requirements from property lines


• Parking provisions (typically one additional space required)


• Height restrictions (usually maximum 2.5 stories)


• Landscaping and screening requirements

Your garden suite must comply with the National Building Code of Canada 2020 edition (effective May 1, 2025 for new applications in NB, with mandatory Tier 2 energy efficiency). This means proper insulation, air sealing, egress windows in bedrooms, interconnected smoke and carbon monoxide alarms, and fire separation if attached to the main house.

You'll need a building permit from the City of Moncton before construction begins. The permit process involves submitting detailed plans showing compliance with both zoning and building code requirements. Expect permit fees of $2,000-$8,000+ depending on the size and complexity of your project.

Trade Permits and Inspections

All electrical work requires a licensed electrical contractor and wiring permit from NB Power (1-800-615-0522). Plumbing and gas work must be done by TIS-licensed trades with proper permits. Final inspections by NB's Technical Inspection Services (TIS) at 1-888-659-3222 are mandatory for all electrical, plumbing, and gas installations.

Realistic Costs and Timeline

Garden suites in the Moncton area typically cost $150,000-$350,000 depending on size, finishes, and site conditions. A basic 600-800 square foot unit with standard finishes runs $150,000-$220,000, while larger units with premium finishes can reach $300,000+. Factor in site preparation, utility connections, and potential septic/well upgrades if you're in a rural area just outside city limits.

The permit approval process takes 6-12 weeks, and construction typically requires 8-12 months from groundbreaking to occupancy. Start your zoning inquiry with the city first – this determines whether your project is even feasible before you invest in architectural plans.

Next Steps

Contact Moncton Planning & Development immediately to verify your zoning compliance and get current ADU requirements. If you're in a rural area outside Moncton's boundaries, you'd work with RSC 11 (Capital Region) instead. Once you confirm zoning approval, connect with local architects familiar with Moncton's ADU requirements to develop compliant plans.

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