By: Thom Gallagher

Building a Legal Accessory Apartment in Your Home

Tags: requirements to build apartment, nanny suite, accessory apartment, basement income, Accessory unit, cost to build a basement apartment

With the prices of homes the way they are, its no wonder people are looking for ways to supplement their income by renting out unused space as Accessory Apartments (also known as second units, in-law suites, granny flats, basement apartments or nanny suites). As rents increase in the GTA and there is a push for more affordable housing options, a basement apartment can fetch as high as $2,500 per month plus utilities depending on size and how well it is designed and finished. But accessory dwellings, as basement units are called by most municipalities, have largely been illegal unless the property has the correct zoning and the unit complies with local building code, at least until now.

Through the Strong Communities through Affordable Housing Act, 2011 and amendments to the Planning Act, the province has compelled municipalities to authorize accessory apartments in detached, semi-detached and row houses that in the past would not have been permitted. Subsequently, each municipality must review their zoning and building code to allow such development while ensuring occupant health and safety.

So, what does that mean to those of us interested in building an accessory unit in our house? There are a number of hoops to jump through with a municipality and their interpretation of the Act. While the province has mandated the following, each municipality may interpret it based on their current zoning and building code application:

As each municipality has slightly different interpretations of the Acts, it is important to consult with your building department before you begin your project. Most municipalities will require detailed drawings of the entire house, including the space being developed into a secondary dwelling, in order to apply for demolition, building and waste bin permits.

Expect to pay $30,000 to $50,000 for a full basement renovation with a legal accessory unit (approximately $70/square foot if using a contractor). Thinking of by-passing the system? Be careful, fines for illegal apartments can reach as high as $25,000 for private homeowners.

For more information on the in’s and out’s of developing an accessory dwelling in your house, or to discuss local real estate opportunities, please call Thom at (416)524-6530.
  1. Fire Protection and Prevention Act, 1997, O. Reg. 213/07: Fire Code;
  2.; Second Units Info Sheet