What is a Secondary Dwelling Unit?

A Secondary Dwelling Unit may also be known as one of these many names:

  • accessory dwelling unit
  • secondary dwelling unit
  • accessory apartment
  • in-law suite
  • granny flat
  • garage suite
  • basement apartment

It is a separate living space with kitchen, bathroom, sleeping and shared laundry facilities or a space with the required connections and hook-ups, that is located on the same property as your house (detached, semi-detached or row house). You can live in it, allow your family members to live in it, or rent it out. It cannot be severed from the lot of the principal dwelling and/or sold.

How do I make my Secondary Dwelling Unit legal?

To be legal, your Secondary Dwelling Unit must be registered with the Township. To register your unit, it must comply with our Zoning By-Law, the Ontario Building Code, the Ontario Fire Code and the Ontario Electrical Code. Here is an overview of the process:

A chart outlining the flow between constructing a new vs existing secondary dwelling unit.

When will I need approvals and permits/inspections?

You will need the appropriate approvals from us and must comply with the: our Zoning By-Law, the Ontario Building, the Ontario Fire and Ontario Electrical Code's. The following helps identify which approvals and permits/ inspections you will need in the stages of constructing your Secondary Dwelling Unit:

Before you build

  1. Check that your Secondary Dwelling Unit meets our [Zoning By-law]. More information on zoning requirements is in the Step 1: Do Your Homework further down on this page. Please contact us for assistance at 613-735-6291.
  2. Submit a building permit application – including any required plans – to us; it will be reviewed by both the Building Department for compliance with the Ontario Building Code and Township's Planning Department for compliance with our Zoning By-Law. More information on building permit requirements is included in the “Step 2: Build Your Secondary Dwelling Unit” section on our website.
  3. A site plan will be required to show that there is parking provided for the proposed secondary dwelling unit and that there is an area available to expand the on-site sewage disposal system to accommodate the secondary dwelling unit. Division B, Sentence 11.4.2.5 (3) The performance level of an existing dwelling unit is reduced where proposed construction which, (a) increases the number of bedrooms in the dwelling unit, (b) exceeds 15% of the gross area of the dwelling unit, or (c) adds new plumbing fixtures to the dwelling unit, will result in the total daily design sanitary sewage flow of the dwelling unit, calculated in accordance with Article 8.2.1.3., exceeding the capacity of any component of a sewage system serving the dwelling unit.
  4. Drawings complete with dimensions must be provided to show the floor plan and the location and materials used for the fire separations for the proposed secondary dwelling unit. The secondary dwelling unit must be a minimum 65 meters square in size to comply with Zoning By-law 08-04-391, I need to be able to calculate this to verify compliance. The drawings must also indicate where the alternate exit is provided and the dimensions of the exit, indicate the location of the smoke alarms and the CO detectors. A schematic should also be provided for the plumbing and electrical alterations.

9.10.9.14. Separation of Residential Suites

The suite must be separated by a fire separation having not less than a 45 minute fire resistance rating, Division B, Sentence 9.10.9.14. Separation of Residential Suites (1) Except as provided in Sentences (2) and (3) and Article 9.10.20.2., suites in residential occupancies shall be separated from adjacent rooms and suites by a fire separation having a fire-resistance rating of not less than 45 min.

(1) Except as provided in Sentences (2) and (3) and Article 9.10.21.2., suites in residential occupancies shall be separated from adjacent rooms and suites by a fire separation having a fire-resistance rating of not less than 45 min.

(2) Sleeping rooms in boarding, lodging or rooming houses where sleeping accommodation is provided for not more than 8 boarders or lodgers shall be separated from the remainder of the floor area by a fire separation having a fire-resistance rating of not less than 30 min where the sleeping rooms form part of the proprietor's residence and do not contain cooking facilities.

(3) Dwelling units that contain 2 or more storeys including basements shall be separated from the remainder of the building by a fire separation having a fire-resistance rating of not less than 1 h.

If the house was built before 2010, the fire separation ratings for floors can be reduced to 15 minutes; where the existing ceiling is finished with drywall and the smoke alarms are interconnected and hardwired to the other smoke alarms in the building. The fire separation rating for the walls can be reduced to 30 minutes, where the walls are existing; (new walls will require 45 min protection; type X drywall)

Houses built after 2010 require separate heating facilities for each suite. In houses constructed before 2010, where the furnace will be shared; a duct-type smoke detector must be located in the supply or return air plenum, which is triggered to shut off the furnace when smoke is present.

9.10.10.4. Appliances and Equipment to be Located in a Service Room

(1) Except as provided in Sentence (2) and Article 9.10.10.5., fuel-fired appliances other than fireplaces shall be located in a service room separated from the remainder of the building by a fire separation having not less than a 1 h fire-resistance rating.

(2) Except as required in the appliance installation standards referenced in Sentences 6.2.1.4.(1) and 9.33.1.2.(1), fuel-fired space-heating appliances, space-cooling appliances and service water heaters need not be separated from the remainder of the building as required in Sentence (1) where the equipment serves,

(a) not more than one room or suite, or

(b) a building with a building area of not more than 400 m2 and a building height of not more than 2 storeys.

Each suite must have an entrance/exit door conforming to the OBC. If a shared corridor is proposed, a second exit is required from each suite; windows are not sufficient as a second exit. A sliding door/patio door cannot be the primary exit.

Division B, Article 9.7.1.3. Bedroom Windows

The basement bedroom window should be accessible as a fire escape.

Bedroom Windows (1) Except where a door on the same floor level as the bedroom provides direct access to the exterior, every floor level containing a bedroom in a suite shall be provided with

(a) at least 1 outside window that can be opened from the inside without the use of tools, and

(b) each such window shall provide an individual, unobstructed open portion having a minimum area of 0.35 m5 (3.8 ft2) with no dimension less than 380 mm (15 in).

Division B, Article 9.10.19.2. Location of Smoke Alarms

Hard wired smoke alarms are required.

(1) Within dwelling units, sufficient smoke alarms shall be installed so that

(a) there is at least one smoke alarm on each floor level, including basements, that is 900 mm (2 ft 11 in) or more above or below an adjacent floor level,

(b) each bedroom is protected by a smoke alarm either inside the bedroom or, if outside, within 5 m (16 ft 5 in), measured following corridors and doorways, of the bedroom door, and

(c) the distance, measured following corridors and doorways, from any point on a floor level to a smoke alarm on the same level does not exceed 15 m (49 ft 3 in).

(2) Smoke alarms required in Article 9.10.19.1. and Sentence (1) shall be installed on or near the ceiling.

(3) Smoke alarms required in Sentences (1) and (2) shall be audible within the bedrooms when the intervening doors are closed.

(4) Smoke alarms required in Sentences (1) and (2) shall be installed in conformance with the manufacturers instructions.

Division B, Article 9.10.19.3. Power Supply

(1) Except as permitted in Sentence (2), smoke alarms shall be installed by permanent connections to an electrical circuit and shall have no disconnect switch between the overcurrent circuit device and the smoke alarm.

(2) Where the building is not supplied with electrical power, smoke alarms are permitted to be battery operated.

The electrical breaker panel for the secondary dwelling unit should be located in that unit, Rule 26-400 Ontario Electrical Safety Code.

Separate water shut off valves for the complete supply to each unit are required, Division B, Sentence 7.6.1.6. Suites(1) Shut-off valves shall be installed in every suite in a building of residential occupancy as may be necessary to ensure that when the supply to one suite is shut off the supply to the remainder of the building is not interrupted.

Once you have your building permit

  1. When your building permit is issued, inspections will be required at certain stages of the construction process. These will be specified to you when the building permit is issued. You must contact the Township's Building Department to book the required inspections.
  2. Electrical work requires a separate permit and Inspection Report from the Electrical Safety Authority (ESA) to ensure compliance with the Ontario Electrical Safety Code. Information on obtaining this permit and Inspection Report is on the ESA's website.

After your Secondary Dwelling Unit is built

You must register your Secondary Dwelling Unit after you have a Final Inspection Report from the Township. Re-inspection for compliance with the Fire Code will occur every 5 years. While the Building Code regulates the construction of the Second Unit, the Fire Code regulates its maintenance and operation after it has been built and registered with the Township. Step 3: Register Your Secondary Unit section of this Guide contains further information.

Planning for a Secondary Dwelling Unit

There are three main steps to building a legal Secondary Dwelling Unit on your Property

Step 1: Do Your Homework

Can I build a Secondary Dwelling Unit on my property?

If you meet all of the basic criteria below, then you should be able to build a Secondary Dwelling Unit on your property. However, you must also meet other zoning requirements (e.g. parking and entrance) as well as the applicable standards of the Ontario Building, Fire, and Electrical Code's. Please contact us at 613-735-6291 to confirm your particular circumstances.

Basic Zoning Criteria:

  • I live in a single-detached house, semi-detached house or a freehold street townhouse;
  • I do not have a garden suite, lodging house or group home on my property already (Note: You can only have one Secondary Dwelling Unit on your property);
  • I do not live in a house within the Ottawa River Floodplain, or on lands in a Natural Heritage Feature zone.
  • I do not live within hazard lands, such as flood-prone or highly erosive areas, or areas with slope stability issues; (this is determined by the planner); and,
  • my lot has adequate servicing to accommodate a secondary dwelling unit; including, but not limited to water supply, waste water disposal and electricity.

Can I build a detached Secondary Dwelling Unit?

Yes, but in order to build a Secondary Dwelling Unit in a detached structure (e.g. garage) you must be able to meet all of the following zoning requirements:

  • Your lot is large enough for an accessory building and is serviced by municipal water and sewer services.
  • Your Secondary Dwelling Unit cannot be more than one storey; and,
  • Your Secondary Dwelling Unit must be able to meet all applicable Zoning By-law provisions, such as minimum setbacks from lot lines.
  • If do not have access to Municipal water & sewer services, your lot must be larger than 0.8 hectares (2 acres)
  • Your detached Secondary Dwelling Unit will also need to meet the standards of the Ontario Building

What are the entrance requirements for a Secondary Dwelling Unit?

All Secondary Dwelling Units must have their own separate entrance. The separate entrance may be from

the front, side or rear of the building, but it must meet the following requirements:

  • The entrance cannot be from a garage, unless there is a separate main door with direct outdoor access;
  • The entrance must be accessed by a minimum 1 metre wide path of travel between the building and any lot line; and,
  • Safe entrance and exit of the Secondary Dwelling Unit must meet the requirements of the Ontario Building Code and the Ontario Fire Code.

How many parking spaces do I need?

You must supply parking for the Secondary Dwelling Unit in addition to the minimum 1 off-street parking space that is required for your home (the principal dwelling).

Please note the following when determining the number of parking spaces on your property:

  • Parking spaces both inside the garage or outside on the driveway can be counted;
  • Any spaces for parking in the boulevard area between the street and your front lot line will not be counted towards these requirements;
  • Each exterior parking space must be a minimum of 2.5 metres wide and 5 metres long;
  • If your property cannot provide enough parking right now, you might be able to widen your driveway to meet the required number of parking spaces;

Can I build a Secondary Dwelling Unit on a privately serviced lot (i.e. individual well and septic)?

Yes, but you may be required to demonstrate that the system has sufficient capacity for the Secondary Dwelling Unit. The Ministry of the Environment has rules for the quantity and quality of water that a private residential well must provide. The capacity and design of a private septic system is regulated by the Ontario Building Code. The minimum lot area is 8,000 m2 (approximately 2 acres).

Do I need to consider on-site drainage?

On-site drainage and storm water management must be maintained or improved with the addition of a Secondary Dwelling Unit. For example, the construction of a side yard walkway has the potential to alter the way surface runoff flows to storm water management drains. A site grading plan may be required to ensure that any changes made to your property do not negatively impact grading and drainage on your property or your neighbours, to limit the possibility of flooding.

What can I do if my property does not meet the zoning requirements?

If your property cannot meet the zoning requirements for Secondary Dwelling Units, it may be possible to apply for approval of either a minor variance or a zoning by-law amendment depending on the circumstance. These processes are summarized as follows.

Minor Variance Application

  • The minor variance process allows for a property owner to seek relief from a specific provision of the Township's zoning by-law subject to the approval of the Committee of Adjustment and no appeals being received. It will typically take about 2 months for your application to be processed. Additional details and the minor variance application form can be found online.

Zoning By-Law Amendment

  • If the requested relief from the Township's Zoning By-Law is not determined to be minor, a site-specific zoning by-law amendment may be required, subject to Council approval and no appeals being received. This process typically takes about 3-4 months. 

Please contact our Planning Department 613-735-6291 to discuss which whether an exception may be possible and which process best suits your situation.

Step 2: Build Your Secondary Dwelling Unit

What are the Building Code requirements for a Secondary Dwelling Unit?

Under the Ontario Building Code, you will need a building and/or a change of use permit. There are different scenarios that apply to Secondary Dwelling Units under the Building Code:

  • Scenario 1: Building a Secondary Dwelling Unit in a new home or house less than 5 years old. Part 9 of the Building Code applies. Submit a building permit application.
  • Scenario 2: Building a Secondary Dwelling Unit in a house more than 5 years old. Part 11 of the Building Code applies. Submit a building permit application.
  • Scenario 3: Secondary Dwelling Unit has already been built without a building permit. Submit detailed floor plans to secure a change of use permit. You may also need to make renovations to your unit, to comply with building or fire codes.

Should I get help to draw my plans?

It is strongly recommended that you hire a qualified designer. The Building Code requirements for Secondary Dwelling Units are complex. A qualified designer will help ensure that your plans meet all technical requirements, saving you time and money in the long run. The designer may be an architect, engineer or a person certified and registered with the Ministry of Municipal Affairs and Housing (MMAH). Designer qualifications can be viewed on the Ministry's on-line Public Registry (QuARTS).

Can my contractor/designer apply for the building permit on my behalf?

Under the Ontario Building Code, the owner is responsible for all construction on your property. If you want your contractor or designer to apply on your behalf, you must provide written authorization, the permit will name you as the owner and correspondence from the Building Department will go to you also.

What does a complete building permit application include?

Once you have checked that your Secondary Dwelling Unit meets the zoning requirements, you can submit your Building Permit or Change of Use Application. Your Secondary Dwelling Unit must comply with the Ontario Building Code. Your building permit application will typically include the following:

  • A site plan showing compliance with zoning requirements such as the number of parking spaces and the entrance path to the Secondary Dwelling Unit
  • A floor plan of the existing or proposed Secondary Dwelling Unit
  • Cross-section drawings of walls/ceilings and details of the materials and systems used
  • Items to be shown on the plans for the Secondary Dwelling Unit include:
    • Entrance and exit
    • Room sizes and heights
    • Door and window sizes and types
    • Fire separations and sound transmission ratings
    • Heating and ventilation system(s)
    • Location of smoke alarms, and CO detectors
    • Plumbing facilities

How long will it take to get a building permit?

After submitting your complete building permit application, it will typically take the Building Department about 10 business days to process it. You will be contacted if further information is required. You can start construction after obtaining the permit.

How much are building permit fees?

Permit fees are reviewed annually and subject to change. All fees are outlined in the Townships Fee Schedule (currently a minimum $125.00).

What should I consider in the exterior and interior design of my Secondary Dwelling Unit?

You should design your Secondary Dwelling Unit so that it blends in with your neighbourhood. Any urban design guidelines that affect your property must be followed. The following are some things to keep in mind when designing your unit so that will be functional and blend in with your home and neighbourhood:

Design Considerations:

  • Match any new windows, doors and materials (e.g. siding, brick, plaster, shingles, etc.) to the current ones on your home, especially at the front of the house
  • Maintain current rooflines if you are adding on dormers or an addition to your second story (e.g. above your attached garage)
  • Build a privacy fence or other landscape screening between your neighbours, especially if the Secondary Dwelling Unit has a side or rear entry
  • Use permeable surfaces when providing additional parking
  • Provide storage space for household items and garbage facilities
  • Provide outdoor amenity space (e.g. deck or patio) for your tenants

Health and Safety Considerations:

  • Accommodate individuals with mobility challenges with appropriate hallway and door widths, bathroom and kitchen fixture placement, stair configuration, etc.
  • Ensure you have adequate outdoor lighting, while still minimizing the projection of light onto neighbouring properties
  • Provide a hard/stable walkway to the Secondary Dwelling Unit entrance if it is not at the front of the house

Service Considerations:

  • Separate electrical service, do you want to include hydro in the rent, or do you want to have them on a separate service & meter? There should be a separate breaker panel for the secondary dwelling unit, you don't want the tenants bothering you every time a breaker trips, what would they do if you were away?
  • Will there be a separate heating system? Will they have their own gas service or propane tank? There should be a separate thermostat to control the heat in the secondary dwelling unit.
  • There will have to be separate water service valves to the secondary dwelling unit, so the tenants can shut off the water to the unit in the event of a break or equipment malfunction.

Step 3: Register Your Secondary Dwelling Unit

The benefits include:

  • It provides safety for you and the occupants, by ensuring that the Secondary Dwelling Unit meets zoning, building, fire and electrical code requirements; while emergency services will be aware that a Secondary Dwelling Unit exists.
  • It allows you to obtain proper home insurance, which gives you peace of mind that you will be covered if you make a claim for damage to your home and be protected against personal liability.
  • You will receive a second municipal address, which in addition to identifying each unit for emergency services, will allow for both the primary unit and the Secondary Dwelling Unit to put out garbage and recycling for collection and for a separate mailbox to be assigned to the Second Unit.

When do I submit my registration application?

After you have built your Secondary Dwelling Unit and had your final inspection from the Building Department, you must apply to register your Secondary Dwelling Unit. A complete application for registration includes the following:

*The property owner must declare the following on the registration form: That you are the property owner or the authorized agent.

How much will it cost to register my Secondary Dwelling Unit? Will I be required to renew my registration?

There is an Application Fee of $120.00. Then there is a one-time registration fee of $200.00. There is also a $50.00 fee for a change in ownership, so the registry can be amended.

Once I have registered my Secondary Dwelling Unit, will it be assigned a separate address?

Yes, once you register your Secondary Dwelling Unit it will be assigned a secondary address of “Unit 2 or Unit B; your choice” (the address for the primary dwelling will stay the same). The address of “Unit 2 or Unit B” must be clearly visible to identify the primary entrance into the Secondary Dwelling Unit. Having a second municipal address will help emergency services such as police, fire and ambulance to act more quickly in an emergency. It will also make mail, delivery services hydro and gas billing more convenient and ensure that garbage and recycling is picked up from both residential units.

Is a list of registered Secondary Dwelling Units publicly available?

Yes, a list containing the addresses of legally registered Secondary Dwelling Units is available for in person viewing at our office located at 460 Witt Road. This list will also make it easier for tenants to identify whether a Secondary Dwelling Unit is legal, (and that it complies with building, fire and electrical codes).

Once I develop a Secondary Dwelling Unit, what are my responsibilities as a landlord?

The rights and responsibility of a landlord are outlined in the Residential Tenancies Act. This information for landlords in Ontario is available from the Landlord and Tenant Board.

All property owners must also follow the Township's Zoning By-Law and Ontario Building Code and Ontario Fire Code provisions, as well as the Township's Property Standards By-law, which establishes standards for the maintenance of properties and buildings, such as interior and exterior yard maintenance.

Download a copy of a Homeowner's Guide to Secondary Dwelling Units


Information Required by Building Department for Applications to Register a Secondary Dwelling Unit

In 2017, Laurentian Valley amended the Zoning By-law 09-04-391 through By-Law 2017-06-028, which now allows Secondary Dwelling Units in most zones of the Township. By-law 2017-06-029, also known as the Secondary Dwelling Unit Registration By-law was also enacted, which requires the registration of all secondary Dwelling Units in the Municipality. (Does not apply to recognized apartment buildings)

Secondary dwelling units — also known as accessory or basement apartments, secondary suites and inlaw flats — are self-contained residential units with kitchen and bathroom facilities within dwellings or within structures accessory to dwellings (such as above laneway garages).

Secondary dwelling units must comply with any and all applicable laws and standards. This includes the Building Code, the Fire Code, Electrical Safety Code, Township Zoning By-law, and property standards bylaws.

To register a secondary dwelling unit the following is required: 
  • Application on Municipal Forms (with all applicable information supplied and forms signed)
  • Site Plan or Plot Plan, showing at minimum the location of the required parking spaces, and the entrance path to the second unit.
  • Floor plans, showing the layout of the Secondary Unit, including room sizes, entrance & exit, door & window sizes and type, fire separation and sound transmission ratings, heating and ventilating systems, location of smoke alarms & CO detectors, plumbing facilities etc. (these can be omitted if they were supplied to obtain a building permit to construct the secondary unit - in which case you just submit a copy of the Occupancy Permit)
All proposed secondary dwelling units on septic systems: 
  • Indicate lot size on the site plan, Minimum .8 Hectares (2 acres)
  • Calculations showing that the existing on-site sewage disposal system can handle the Daily Design Load, or indicate Septic Permit Number that was granted for the proposed use as a Secondary Dwelling Unit.
Any proposed secondary dwelling in the Ottawa River Flood Plain: 
  • Elevation Survey prepared by Ontario Land Surveyor, showing that the secondary dwelling unit will not be impacted by a flood

Download the application to register your Secondary Dwelling Unit