Additional Residential Units

Planning your ARU Project

• Zoning

  The City of Barrie allows up to four residential units per lot in residential zones. That means you can add up to three ARUs to your existing home, subject to zoning compliance. Eligible property types include single detached homes, semi-detached homes, townhouses or rowhouses, and accessory buildings (e.g. coach houses or garages). 

  Check your zoning using the interactive Planning and Development map. An ARU must conform to all standards for your zone, including:

  • 1 parking space per unit for each ARU added to the property
  • A minimum 1.2 m wide access path to the unit from the street or parking area 
  • Setbacks from property lines
  • Maximum building height and size (for detached ARUs)
  • Landscape buffer areas around detached ARUs 
     

  For full details please see Section 5.2.9 of Zoning By-Law.

• Conservation Authority Areas

  Is your property near a watercourse of natural hazard area? Check if you’re in a regulated area using the mapping linked below:

  • Lake Simcoe Region Conservation Authority (LSRCA) 
  • Nottawasaga Valley Conservation Authority (NVCA) 
     

  If your property is regulated, you’ll need a permit from the Conservation Authority before applying for a building permit.

• Site Design & Layout

  Design your ARU to fit your home and neighbourhood. Consider location and orientation, building height and materials, privacy for all units and neighbours, and drainage and grading (to prevent flooding). Your site plan must show:

  • A clearly defined entrance (separate or shared)
  • Safe pedestrian access from the street or driveway (minimum 1.2 metres wide)
  • At least one parking space per unit (minimum size of 5.5 metres long by 2.7 metres wide). Spaces may be stacked/tandem, but you must show all parking for existing units and the ARU on your site plan.
     

  Additional considerations include:

  • Tree protection: Avoid removing mature trees when possible. If trees on or near property lines may be affected, injured or removed, you will need written permission from neighbours.
  • Heritage property? You may need approval for alterations. For questions about altering your heritage property, please contact heritage@barrie.ca or 705-739-4220 x4416.
  • Working near sidewalks or roads? A Right Of Way Activity (ROWA) Permit is required if you will be doing work within the City of Barrie Right of Way, which includes sidewalks, roads, boulevards, and the area where your driveway connects to the street.
• Site Servicing

  ARUs must connect to municipal water and sewer services, where available. Only one connection per property is allowed. If upgrades are needed (e.g., larger pipes or new service lines within your property for a detached ARU), you’ll be responsible for the cost, and likely need a ROWA permit.

• Ontario Building Code

  Your ARU must meet Ontario Building Code (OBC) standards for safety and livability. When choosing your design, you can:

  • Use plans from the City’s design catalogue for detached ARUs (see more information below)
  • Choose plans from other design catalogues such as the plans offered by the Canadian Mortgage and Housing Corporation (CMHC)
  • Hire a qualified designer or architect for custom plans
     

  Please visit the City’s Residential Building Permits webpage for guides and resources.

• Ontario Fire Code

  Several updates to the Ontario Fire Code (O. Reg. 213/07) took effect January 1, 2026, including important changes that impact additional residential units. Property owners must ensure their homes and rental units comply with these updated life-safety requirements.

  Under the updated Fire Code, carbon monoxide (CO) alarms are required in more types of units than before. Get full details on where CO alarms must be installed.

  Additional Fire Code changes relate to:

  • Maintenance and testing of life-safety systems
  • Definitions and referenced technical standards
  • Certain multi-unit residential building requirements
     

  While not all changes directly affect every ARU, property owners should be aware that other life-safety provisions may apply depending on your building’s design and features.

  Owners are encouraged to:

  • Confirm CO and smoke alarm requirements for their specific property
  • Review the full Ontario Fire Code 
  • Contact Barrie Fire & Emergency Service at fire.prevention@barrie.ca or 705-728-3199 with questions regarding compliance for ARUs
  • Ensure your unit meets all applicable Fire Code requirements; this is essential for safety and for successfully completing the Second Suite Registration and Inspection process
• Financing your ARU

  You should budget for the design, permit fees, material and construction costs of your ARU and for any servicing upgrades required.

  The County of Simcoe Secondary Suites Program provides funding of up to $30,000 per unit for the creation of ARUs in exchange for providing the ARU as an affordable rental unit. Barrie homeowners could also qualify for an additional $15,000 Barrie Bonus top-up through the City’s Housing Community Improvement Plan.

  The CMHC Refinance program allows homeowners to refinance their existing properties and create ARUs. See their website and talk to your mortgage lender for more information.

  You may also qualify for the Multigenerational Home Renovation Tax Credit (MGHRTC). This federal program helps cover the cost of creating a unit for a senior or adult with a disability to live with family. 

• Renting or Living in your ARU

  Your ARU will automatically be registered with the City, assigned a municipal address, and added to the City’s map of ARUs once you have built your unit and completed required building permit inspections. This will ensure you receive mail, emergency services, and waste collection for the new unit.

  If you’re thinking about renting out the unit, below are some helpful resources:

  • Guide to Ontario’s standard lease, including information on rental rules, rights and responsibilities of landlords and tenants under the provincial Residential Tenancies Act
  • Regional Housing Support Services from Empower Simcoe – includes both landlord and tenant support resources, including housing lists of available rentals, mediation services, and their new Housing Retention Fund

• Step 1: Know your Property

  Before you begin planning your project, it is important to gather detailed information about your property. Start by reviewing:

  • Property lines 
  • Setbacks to property lines of existing buildings
  • Any easements and rights-of-way
  • Encroachments, such as shed, fences, or other structures that might not be fully on your property
  • Protected services, including utilities, rear yard infiltration galleries, or certain areas where site grading has been designed to manage water run off 
     

  If you do not have an existing survey, or don’t know where your property lines are, you can contact Ontario Land Registry Office to look up any historical records for your property, or hire an Ontario Land Surveyor to complete a new survey of your property. 

  Property line parcel data shown on the Discover Barrie Portal is offered only as a general guide and cannot be used in place of a survey. 

• Step 2: Know your Zoning

  The zone of your property tells you where you can locate an ARU on your property. To look-up your zoning:

  1. Visit the City of Barrie interactive mapping tool
  2. Turn on the “Zoning By-law – In Force” layer under the “Land Use Planning" heading
  3. Type your property address into the search bar and the interactive map will zoom to your property
  4. Click on your property and identify your zone – you will need this to know what standards you need to follow in the Zoning By-law. 

  In Barrie, up to four residential units on residentially zoned properties is permitted, including single-detached homes, semi-detached homes, and townhomes. These units are subject to meeting all applicable standards outlined in the City’s zoning regulations.

  The Zoning By-law applies to a range of residential zones, standards for detached ARUs can be found under section 5.2.9 for all R1, R2, R3, R4, RM1, RM1-SS, RM-2, and RM2-TH zones, and under section 14.5.2 for R5 and NMU zones.

  Need help to understand zoning requirements?  Contact the City’s Planner of the Day at 705-739-4220 x4208, planneroftheday@barrie.ca or visit City Hall in person.

  Once you know your property’s zone, and the standards specific to your zone and ARU, you’ll see where an ARU could go on your lot.

• Step 3: Choose a Design

  Browse the standardized designs, and consider the layout, number of units and size of the building. Note that a variety of unit layouts, and duplexing options may be available, and each design will need to be situated to your property, or lot, configuration. 

  A building permit will always be required to facilitate the use of a standardized design. This is to accommodate any minor changes that could be required to place an ARU on your property, to account for any potential design changes you would like to make with the designer, and to ensure that wherever your ARU is situated, it complies with the Barrie Zoning By-law and Ontario Building Code.

• Step 4: Contact a Designer

  Once you have chosen a design you’re interested in, contact the designer for more information about purchasing the full set of plans, the contract, and fees related to their consulting services to tailor the stock plans to your site, and to assist in making a building permit application. As you continue with your project, you can use additional building-related resources provided by the City. 

  Note: The City of Barrie is not involved in any monetary exchange for the purchase of designs or related professional services, and contact information provided here is as a convenience only, not an endorsement. The contractual relationship to any designer remains solely between you – the applicant – and the designer. Please review the disclaimer below, prior to proceeding.

  The City of Barrie is providing the Additional Residential Units Designs to the User on an "as is" basis. The City does not guarantee that the Designs comply with all legal requirements, including those of the Ontario Building Code and the City’s zoning by-laws. The City makes no representations or warranties and expressly disclaims any and all warranties, express or implied, regarding the Additional Residential Units Designs, the Designs therein, and the Designers, and will not be liable for damages of any kind arising from the User’s use of the Additional Residential Unit Design, or any Designs, or any act or omission of any Designer. All Designs require a building permit application, which will not be expedited or automatically approved by the City. The User releases and holds the City harmless for any losses that may arise from the User’s use of the Additional Residential Unit Designs, and the Designs. The City is not a party to and will not facilitate any agreement or monetary transaction respecting the Designs or additional service.

• How do I know if I am allowed to have an ARU on my property?

  To determine if your property is eligible for an ARU you must confirm the following:

  • Property is in a residential zone that allows ARUs 
  • Property is not in a hazard zone 
  • Property is not a designated heritage property unless heritage approvals are obtained
• Can I build multiple ARUs on my property?

  Yes, the Zoning By-law permits up to four dwelling units on residentially zoned properties subject to applicable regulations.

• What if I don’t meet all the zoning standards to build an ARU on my property?

  If you can’t meet all zoning requirements to build an ARU because of site constraints, you may be able to apply for a minor variance through the Committee of Adjustment to move forward with your project. City staff verify you meet zoning during the permit review process and reach out with options if you do not. To learn more, please visit our Committee of Adjustment webpage.

• How many parking spaces are required to permit one or two ARUs?

  One parking spaces is required for each dwelling unit. If you are adding one ARU to your property, and have an existing home, you will be required to provide two parking spaces.

• Does the garage count toward tandem parking limits?

  A parking space within a garage may be used in a tandem configuration. This may not be permitted for private communities, such as condominiums. Please always confirm with the Planner of the Day.

• With two legal units in the primary residence, is 1.5 parking spaces per unit correct—meaning three total required spaces?

  No, the City's Zoning By-law 2009-141 was amended by By-law 2024-043, that when creating an ARU, the parking rate is reduced to one space per dwelling unit.

• If the driveway is widened to fit multiple cars, what are the parking requirements for ARUs?

  Section 5.3.6.1 of the Zoning By-law (pg. 5-15) controls front yard parking on private property. Depending on your zone, you may only park within a certain area of your front yard. For help to understand your property’s zone, please contact the acting Planner of the Day.

• How many parking spaces support four units?

  At minimum, four parking spaces are required, at a rate of one space per dwelling unit.

• Will my property tax go up if I construct ARU(s) on my property?

  The City of Barrie does not assess property values. This is done by the Municipal Property Assessment Corporation (MPAC). Your assessed property value may change; more information can be found at mpac.ca. 

• Are there any costs with building an ARU?

  Although you do not need to pay a professional for a set of drawing plans if you choose to use a plan from the City of Barrie’s Design Catalogue you are still required to pay for the following:

  • Building permit fee;
  • All construction costs;
  • Hiring a builder;
  • Upgrades or connections to municipal sewer and water services (if applicable)
  • Development Charges (if applicable)*
     

  *Up to two ARUs per property may be exempt from development charges; however, subsequent ARUs constructed on your property will incur development charges.

• Does this trigger a Site Plan Approval process?

  No, a Site Plan Approval process is not required for residential development of less than 10 dwelling units.

• Should I contract an Ontario Land Surveyor (OLS) to confirm setbacks, coverage, and parking dimensions?

  Yes, an OLS survey will be required. Please ensure all zoning details are included.

• Can ARU servicing connect through the primary home’s existing services, or are separate lateral connections from the street still required?

  Separate lateral connections are required. The City takes a firm stance on the Ontario Building Code, Sentence 7.1.2.4. (2) of Division B, and therefore, connections through an existing building cannot be supported.