Additional Dwelling Units

Click here for the Additional Dwelling Unit Information & Application Guide

What are Additional Dwelling Units?

Additional Dwelling Units (ADUs) are a separate dwelling unit from the main dwelling unit and are located either in the same building as the main dwelling or in an accessory building, or part thereof, which is located on the same lot as the main dwelling.

Additional Dwelling Unit Example Diagram

ADUs are separate living spaces from the main dwelling unit with a kitchen, bathroom, sleeping and sanitary facilities. ADUs take many forms including: attached to the main dwelling, for example a basement conversion or addition, or as detached housing unit, for example a converted detached garage or in an accessory building.

As ADUs are not permitted to be severed from the main dwelling the ownership of these units coincides with the ownership of the main dwellings; however, they can be rented to other individuals. ADUs can be a significant resource for the rental market and are a step towards addressing affordable housing in urban and rural areas.

An Additional Dwelling Unit may also be referred to as:

  • Second Dwelling Unit
  • Accessory Apartment
  • In-law Suite
  • Garden Suite
  • Basement Apartment
  • Garage Suite

Where and How Many ADUs will be Permitted?

Under Zoning By-law No. 79-200:

A maximum of 2 ADUs can be located on a parcel of urban residential land which is within the Urban Area Boundary on which residential use is permitted and is served by municipal sewer and water services, subject to meeting all zoning regulations.

A maximum of 1 ADU can be located on a parcel of rural land which is outside the Urban Area Boundary on which residential use is permitted and is served by private sewer and water services, subject to meeting all zoning regulations.

RestrictionsParcel of Urban Residential LandParcel of Rural Land
Permitted Zones
  • R1A-R1F
  • R2
  • R3
  • DC
  • DTC
  • TRM
  • A
  • R
Permitted Dwelling Type
  • Detached dwelling
  • Semi-detached dwelling unit
  • On-Street townhouse dwelling unit
  • Duplex dwelling
  • Detached Dwelling
Maximum No. of ADUs

2

1

Composition

Detached, Semi-detached, On-street Townhouse Dwelling Unit:

  • Two interior/attached ADUs
  • One interior/attached ADU and one exterior/detached ADU

Duplex Dwelling:

  • One interior/attached ADU
  • One exterior/detached ADU

Detached Dwelling:

  • One interior/attached ADU
  • One exterior/detached ADU
Maximum No. of Dwelling Units

For a TOTAL maximum of 3 dwelling units on a lot.

For a TOTAL maximum of 2 dwelling units on a lot.

Urban Residential Land Diagram showing a maximum total of 3 units
Rural Land Diagram showing maximum of 2 dwelling units

What Regulations Apply?

Parking

  • 1 parking space is required per ADU, which may be provided in tandem. On-street parking is not permitted

Servicing

Urban - ADU must connect to existing municipal infrastructure.

Rural - ADU must connect to the existing septic system if it was constructed with the capacity to accommodate the additional flows, if not, a new septic system will need to be constructed.

ADUs in Accessory Buildings

Setbacks:

  • Rear yard setback – 1.2 metres
  • Interior side yard setback - 1.2 metres
  • Units are not permitted to be in a front or exterior yard.

Lot Coverage - The overall percentage of maximum lot coverage for each zone applies, the maximum lot coverage for an ADU in an accessory building is 93 square metres provided that it does not exceed the overall maximum lot coverage permitted by the zone.

Height - Cannot exceed 7 metres in height.

Rural ADUs

  • Rural ADUs in accessory buildings cannot be located no more than 15 metres from the detached dwelling.
  • ADUs cannot be permitted within a building/structure used for any agricultural use.
  • Must meet Minimum Distance Separation requirements.

Additional Dwelling Unit Requirements

A Building Permit is required in the City of Niagara Falls for any ADU.

Before applying, applicants must obtain:

  • A Zoning Compliance Certificate, issued by the City of Niagara Falls
  • Supporting plans

ADUs must comply with both Official Plan policies and Zoning By-law regulations.

Before applying, applicants should confirm:

  • What is being proposed is permitted
  • That applicable zone regulations (setbacks, coverage, height etc.) can be satisfied
  • That parking for each unit can be provided on-site (on-street parking is not allowed)

For an ADU to qualify as an authorized unit, it must satisfy:

  • Ontario Building Code health and safety requirements
  • Fire and Electrical Codes
  • Occupancy Standards
  • Property Standards

Municipal servicing is available (or private servicing for rural ADUs)

Frequently Asked Questions

How many ADUs can I have on my property?

If your property is within the Urban Area Boundary and has a detached dwelling, semi-detached dwelling, duplex dwelling, or on-street townhouse as a permitted use, you are permitted to have two ADUs on your property to a maximum of three dwelling units on a single lot.

If your property is outside of the Urban Area Boundary and has a detached dwelling as a permitted use, you are permitted to have one ADU on your property to a maximum of two dwelling units on a single lot.

Do I need to provide parking for my ADU?

Yes, one parking space is required per ADU which may be provided in tandem.

On-street parking does not satisfy parking requirements and is not permitted.

Do I need a permit to build an ADU?

Yes, a building permit is required to build an ADU.

For more information, please contact the Building Department.

Do Development Charges apply to ADUs?

To encourage the supply of smaller housing units, the Province of Ontario has exempted Development Charges and parkland dedication requirements for ADUs (under Bill 23)

What kind of fees will apply to an ADU project?

Building permit fees for ADUs are calculated based on a rate for the finished floor area, there are different fees for an interior ADU (within the main dwelling) and for an exterior ADU (in an accessory building). To determine which fee rate would apply please see the building permit fees

For more information, please contact the Building Department.

Do ADUs need a separate address?

While the property may have the same municipal address, additional units will be identified with a unit address. A unit address will be assigned by the City following a Building Permit application being made. This address will be assigned as a secondary address to the property to ensure the safety of the people residing in any dwelling units and for emergency response.

Can ADUs be severed and sold separately?

No, the City’s Official Plan prohibits the severance of ADUs from the main dwelling and Staff will not be able to support severance applications due to the City's Official Plan policies and Provincial policies.

A Zoning By-law amendment will be required to permit a semi-detached dwelling, where not permitted under the property’s zone, to facilitate a severance.

Can I rent out my ADU as a vacation rental (e.g. Airbnb or VRBO) or a bed and breakfast?

ADUs in residential zones cannot be used as a Vacation Rental Unit (VRU).

Vacation Rental Units are only permitted in designated zones including: the Tourist Commercial (TC), General Commercial (GC), or Central Business (CB) zone.

If an ADU is located in one of the zones listed above it may be able to be used as a VRU but it must meet all of the City’s VRU policies, required zoning provisions, and provide an additional two parking spaces per unit.

More information on the City’s VRU policies

Will ADUs affect my property taxes?

Your property taxes may be affected by the creation of an ADU as the number of dwelling units on a property contribute to its valuation. Property taxes are based on the value of your property.

Please contact the Municipal Property Assessment Corporation for more information on your property’s assessment.

Municipal Property Assessment Corporation

Contact Us

City of Niagara Falls Planning Department
[email protected]
(905) 356–7521 ext. 4330

City of Niagara Falls Building Department
[email protected]
(905) 356–7521 ext. 4001