City of Ottawa Nears Completion of Coach House Consultation


The City of Ottawa may be loosening the rules regarding “Coach Houses”, a type of secondary dwelling unit (SDU). Coach Houses are essentially small apartments or suites in the backyard of a home or along a laneway. Generally speaking, these types of SDUs are used to infill and support urban intensification goals by providing opportunities to introduce more dwellings in established neighbourhoods and broaden affordable housing options. The City of Ottawa defines SDUs as:

a separate dwelling unit subsidiary to and located in the same building as an associated principal dwelling unit; and its creation does not result in the creation of a semi-detached dwelling, duplex dwelling, three-unit dwelling or converted dwelling.

The province of Ontario, through the Strong Communities through Affordable Housing Act, 2011 requires municipalities to authorize second units in detached, semi–detached and row houses, as well as in ancillary structures. The current restrictions and limitations for all SDUs are set out in the City’s Bylaw found here. The City of Ottawa currently permits SDUs within primary residential buildings in all residential zones, but not as accessory structures as-of-right, like a detached garage.

Ottawa is currently undertaking a zoning study to determine the appropriate zones and standards to permit SDUs within accessory structures, in residential neighbourhoods. While the study is ongoing and formal results will not be readied until the fall of 2016, the initial public consultation period has completed. The preliminary results were released in April, and can be reviewed in full here. At this stage, while the existing legislation was mostly considered adequate, six key suggestions emerged:

  1. SDUs should not be on private services: SDUs should not be permitted on a lot serviced by a private well and septic system. The main concern is the impact on water quality and quantity issues that should be considered during the assessment of SDU’s suitability.
  2. Maximum size – SDUs should be limited in size to no more than 40% of the footprint of the principal dwelling unit on the lot, up to a maximum footprint of 95 m2.
  3. Maximum height– Generally, the proposed limit would be that a SDU would be allowed a maximum height of one storey, except: a) for lots with access from a travelled public lane, or b) where the SDU is located within a detached garage where the use of the garage for parking is being retained and the dwelling would be above the garage. The primary issue to the stakeholders was maintaining reasonable privacy.
  4. Include a grandfathering clause for existing structures – Many comments requested that a grandfathering clause be included in the Zoning By-law provisions to allow existing accessory structures, which do not meet the provisions to be permitted, to convert into a SDU.
  5. Permit SDUs on properties with a duplex, provided: (a) it does not change the streetscape character along the street on which the principal dwelling fronts (b) it is serviced from the principal dwelling unit on the lot, which must be serviced by a public or communal water and wastewater system (c) it must be located on the same lot as its principal dwelling unit (d) it must be located in the rear yard of the principal dwelling or in the case of a lot with frontage on both a street and a public lane, it must be located in the yard adjacent to the public lane
  6. Limiting owners to one SDU per primary home – This recommendation would mean that only one Coach House or SDU would be permitted, thus people would be prohibited from adding one on a lot where the principal dwelling already has a secondary dwelling unit, garden suite or any rooming unit.

We expect more detail and further updates when the final report is presented to City Council. This is anticipated in the fall of 2016.

For more information on this study, or to receive project updates, email and request to be added to the City’s distribution list.

Kate Agyemang

Law student