Additional Residential Units

An Additional Residential Unit (ARU), or also known as Additional Dwelling Unit (ADU), Granny Suite, In-Law Suite, Basement Apartment, is a self-contained residential dwelling unit separated from the main dwelling located on a lot.  An ARU may be located within the same building as the primary residential dwelling or in a detached accessory structure on the same lot as the primary residential dwelling.  ARUs are only permitted where a primary residential unit is a single detached, semi-detached or townhouse dwelling.

On this page:

• Registering my ARU
• Building Permit and ARUs
• Septic Permit and ARUs
• Overview of regulations relating to ARUs
• General requirements for ARUs
• Agency Contact Information
• Frequently Asked Questions
• Additional Residential Unit Register

Registering my ARU

All ARUs must be registered under By-law 2020-162 (download). Units previously registered under the Town of Lindsay By-law 97-169 and the City of Kawartha Lakes By-law 2014-305 are considered legally registered for the purposes of the current by-law. Unregistered ARUs are considered illegal.

The purpose of the Registration By-law is to ensure that all ARUs in Kawartha Lakes are safe and legal. The Registration By-law allows the City to maintain a complete inventory of all single detached dwellings, semi-detached dwellings and townhouse dwellings that contain ARUs,

The registry is used by Emergency Services (Fire, Police, EMS) when responding to emergencies, the City’s Solid Waste Division for garbage collection and by other agencies such as the City’s Planning Division when calculating dwelling unit densities of neighbourhoods.

An application for registration must be filed with accompanying paperwork and applicable fee to the Building and Septic Division. Please note that where more than one ARU is proposed on a lot, each ARU must be registered individually.

There is a one-time fee required to accompany the application for registration, which can be found in the Consolidated Fees By-law 2018-234 (download). There will also be associated building permit fees applied, if a building permit is deemed by Building and Septic Division staff to be required, with respect to required upgrades or new construction.

As part of the registration process, an inspection will be required to ensure the safety of the owner and tenants of the ARU. The inspection may be performed by a Building Inspector or by a Building Inspector in conjunction with a Fire Prevention Officer. The inspector(s) will confirm compliance with applicable regulations and will require access to all areas within all dwelling units.

Once an ARU is registered, the owner will receive a letter of registration from the City.

Building Permit and ARUs

In most cases, a building permit will be required to create or register an ARU. Most ARUs will require Ontario Building Code modifications to comply with registration requirements.

A building permit addresses items such as:

• access/egress from the unit
• fire separations between units and other shared spaces within the building
• room and window sizes
• locations for smoke detectors and carbon monoxide detectors
• heating and ventilation system requirements
• any other items applicable to your site

The property owner or a qualified designer can prepare the drawings required for the building permit application. Drawings must show all Ontario Building Code requirements. Upon submission of a complete application, a building permit will be issued within 10 business days.

Septic Permit and ARUs

In many cases, the existing sewage system will not be adequate for the increased usage and a new sewage system or upgraded sewage system will be necessary.

ARUs proposed on properties serviced with a private on-site sewage system will require a review of the existing system components and capacities. Contact your area Septic Inspector at septicpermits@kawarthalakes.ca to start a conversation around the requirements for applications and permitting for private on-site servicing.

Overview of regulations relating to ARUs

(a) Ontario Building Code:

Please refer to the Ontario Building Code for exact provisions relating to ARUs.

(b) Zoning By-law:

If you would like to look up your own zoning, please visit City Maps to look up your property on the map and visit the Planning and Development Page to review the applicable zoning by-law.

(c) Ontario Fire Code:

Please refer to the Ontario Fire Code for exact provisions relating to additional residential units.

Property owners should be aware that bringing existing dwellings that contain an ARU into compliance with the Ontario Fire Code regulations may require alterations for which a building permit is required under the Building Code Act.

General requirements for ARUs:

• Compliance with the Ontario Building Code, Fire Code, Zoning By-law and any other municipal and provincial standards
• The lot has adequate sewage and water supply
• If on private services, the lot area is at least 0.4 hectares (1 acre) in size
• The lot fronts on and has access to an improved public street, maintained year-round
• The lot is not used for a bed and breakfast establishment
• The primary residential unit meets the parking requirements in the Zoning By-law
• The floor area of a proposed ARU is equal to or less than the floor area of the primary residential unit
• If located within the Oak Ridges Moraine Area, a maximum of one ARU may be located in the same building as the primary residential unit, being a single detached dwelling - detached ARUs are not permitted
• In all other areas, up to two ARUs for every primary residential unit are permitted, where either: 
  • one ARU is located within the same building as the primary residential unit and the other ARU is in an accessory building, or
  • two ARUs are located in the same building as the primary residential unit.
• The ARU is not located within a sensitive land use area, as represented by one of the following categories: EP Zone, HL Zone, OS Zone, ORMCA Zone, ORMLA Zone, ORMEP Zone, floodplain area, water setback or other hazardous lands
• The ARU complies with the Minimum Distance Separation formulae from neighbouring livestock barn, manure storage and/or anaerobic digester
• Where an ARU is located on an upper storey of an accessory building or structure, alternate zoning provisions are available with respect to the height and minimum setbacks of the accessory building or structure:
  • height may be increased to 10m, and
  • interior side yard and rear yard setbacks are permitted to be no less than 1.2m to lot lines

Agency Contact Information

Building and Septic Division: 705-324-9411 extension 1288 or e-mail buildingpermits@kawarthalakes.ca

Fire Prevention Division: 705-324-9411 extension 3650 or e-mail fireprevention@kawarthalakes.ca

Electrical Safety Authority: 877-372-7233 or visit their website.

Conservation Authority: City of Kawartha Lakes is covered by three different Conservation Authorities and you will need to visit the website that applies to your property. Conservation mapping can be found at camaps.ca

To locate a qualified designer, use the Ministry of Municipal Affairs and Housing QuARTS registration site.

Frequently Asked Questions

How do I obtain an address/sign for my ARU?

Upon completion of registration, a municipal address number will be assigned to the ARU by the City.  It is the owner’s responsibility to display the address so that:

• it is visible from the street
• the location of the unit is clearly indicated on the building face and is visible upon approach down the driveway
• directional arrows direct Emergency Services personnel to the unit's entrance door   

In urban areas the property owner shall supply the unit number sign.  In rural areas, the property owner may request a green sign blade from the City, but note there is a fee for the sign and the property owner must install the sign themselves.

Can my tenant park on the street?

Please be aware that vehicles illegally parked on the street will be ticketed and no exceptions will be made for ARUs. Before creating an ARU, please consider the parking needs for all units and ensure the combined parking needs can be  accommodated wholly on the subject property.

Can I sever an ARU from the primary residential unit?

An ARU within an accessory building or structure is not eligible for a severance from the primary residential unit. An ARU, by definition, must be located on the same lot as its primary residential unit.

Can I use my ARU as a Short Term Rental?

For information on Short Term Rental program and how to license a unit please visit our Short Term Rental page.

Does my ARU need to share my existing driveway?

Not always.  If you wish to propose a separate driveway entrance for your ARU you must first obtain an entrance permit from the City.  For information on applying for an entrance permit please visit the Entrance Permits page.