Additional Residential Units - FAQ's

What is an Additional Residential Unit?

An Additional Residential Unit (ARU) is a self-contained dwelling unit located within a single detached, semi-detached or row house (secondary to the primary residence) or in a detached structure on the same lot as the primary residence. 

Provincial legislation states that, up to three units may be permitted subject to compliance with the Zoning By-law.  Additional Residential Units by definition have independent cooking, sleeping and bathing facilities and direct access to the outside.

The Township of Essa supports Additional Residential Units/ARUs as a means to assist with the current under-supply of housing stock for the long term. 


Additional Residential Units/ARUs are allowed in the Agricultural, Rural, and Residential (R1, R2, R3, and RS1) Zones subject to certain exclusions and criteria in the Zoning By-law.

Yes, an application to register an existing ARU, under By-law 2022-XX, is required – once the new Zoning By-law Amendment is adopted. When constructing a new ARU, an application for a Building Permit is also required.  An application for a Building Permit may also be required for an existing unit.

Section 9.8 of the Ontario Fire Code sets out minimum provisions for fire safety in existing residential buildings which contains two existing dwelling units in existence on July 14, 1994 including fire separation standards, means of egress, Electrical Safety Authority (ESA), and inspection requirements.

The Ontario Building Code applies to all units created after July 14, 1994. The Code sets out requirements for all buildings and dwelling units and they include but not limited to fire separations, fire alarms, room height and size, window size and egress, plumbing, electrical and lighting.  A permit will be required for all construction.

An increase resulting to a landowner’s taxes would be based on MPAC’s assessment of the property.

The NVCA has not prohibited ARUs in their Regulated Area, however, a permit would be required in accordance with their standards for issuance. ARUs would not be permitted in NVCA Regulated Areas that are hazardous.

The current municipal Zoning By-law requires a minimum of 2 outdoor parking spaces per each dwelling unit. The proposed Zoning By-law Amendment maintains this standard in keeping with Council direction.  All parking must be on private property so as not to interfere with snow clearing operations. 

Temporary Rentals are either part of, or an entire dwelling unit, that is rented out for 28 consecutive days or less, for the short term for compensation, i.e. an Air B n B which is rented for a week or weekend.  Temporary Rentals therefore do not assist with alleviating the under-supply of long-term housing and will not be permitted as Additional Residential Units.

Garden Suites, also commonly referred to as Granny Flats, are a detached residential dwelling containing a kitchen, bathroom and sleeping accommodations set out to care for seniors ‘at home’.  They are ancillary to the primary residence and may be portable in nature (ie a modular home).  They are not permanent in accordance with the provincial Planning Act whereas ARUs are meant to be permanent dwelling units to assist with the under-supply of housing stock for the long term.

In 2022, the Province of Ontario published a Housing Affordability Task Force Report that makes recommendations as to how the province can move forward with increasing housing supply.  Of the many recommendations resulting from this Report, increasing density, where it can be accommodated through local policies and zoning, is one approach that has led to the Additional Residential Units program.

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