Accessory Suites

Cochrane's Municipal Development Plan (MDP) identifies the importance of providing a range of housing options to suit all ages and income levels. To help provide options, the Town allows accessory suites as a discretionary use in certain residential districts. Accessory suites are approved on a first-come, first-served basis to a maximum of 10% of lots in a neighbourhood. There are three common types of accessory suites:

  1. basement suite: a self-contained dwelling within a lower floor in a principal building.
  2. garden suite: a self-contained dwelling unit located in the rear yard of a residential lot upon which an existing dwelling unit is located.
  3. accessory building suite: a self-contained dwelling within a second floor of an accessory building (garage).

Accessory Suite and Garden Suite Regulations

  • A maximum of one accessory suite or garden suite is allowed on a property.
  • Must provide two parking stalls for the principal dwelling and one parking stall per bedroom in the proposed suite on the property. Street parking is not considered.
  • The parking area must be hard-surfaced (ex. concrete, asphalt, interlocking blocks).
  • The suite must not exceed 40% of the gross floor area of the house.
  • The suite must be a minimum of 30m2.
  • A garden suite, or an accessory suite located above a garage, shall be setback a minimum of:
    • 1.2m from the rear property line
    • 1.2m from the side property lines
    • 1.83m from the house and other accessory buildings on site.

NOTE: please contact planning services for more regulations with regards to a garden suite or an accessory suite above a garage.

Thinking about building an accessory suite?
Step 1: discuss your proposal with Planning staff as soon as possible. We can provide early guidance, describe the process and ensure you are headed in the right direction.

Step 2: fill out a Development Permit Application

Tip: use the Accessory Suite Checklist to make sure you have everything you need.

Step 3: apply for a building permit and, if applicable, electrical, plumbing and gas permits (after the Notice of Decision is issued).

What happens next?

Once we receive your Development Permit application for an accessory suite, Town staff do a thorough review and determine if there is sufficient information to make a decision. If we need more information, we'll get in touch to let you know what's missing. 

The completed application is circulated to various Town departments and outside agencies for comment and we conduct a site visit. We'll let you know if there are any comments so you can address them.

The application then goes to the Cochrane Planning Commission (CPC) which meets on the third Wednesday of each month. CPC may approve the application, place conditions on the approval or cite reasons for refusal. The decision of CPC is advertised to adjacent landowners and published in the newspaper to allow opportunity for an appeal.


CPC decisions may be appealed to the Subdivision and Development Appeal Board. To appeal,complete and submit a Notice of Appeal form within 21 days of the Notice of Decision appearing in the local newspaper.


Once all the conditions of the development permit and building permit have been satisfied, your accessory suite is ready for occupancy!