What second suite conversion actually costs in Toronto

What actually moves the price

Ceiling height, and whether you have enough of it. A second suite has to meet a minimum height, and a great many Toronto basements are short of it. If yours is, the honest answer is that you are not doing a $35,000 basement apartment; you are doing an underpinning job first and a suite afterwards, and the combined figure looks nothing like the distribution above. Measure before you budget. Ourbasement underpinning page has the numbers for that half.

Egress. A bedroom needs a compliant means of escape, which in a basement usually means cutting a window opening into the foundation wall and building a window well. That is concrete work, not carpentry, and it is a common surprise on quotes that were priced off a floor plan without anyone looking at the walls.

Fire separation and alarms. The suite has to be separated from the rest of the house to a required rating, and alarms have to be interconnected across both units. This is unglamorous, invisible when finished, and not optional. A quote that omits it is cheaper because it is not a legal suite.

Heating and ventilation. Whether the existing system can serve two dwellings or whether the suite needs its own arrangement changes the number materially.

Why doing this legally is worth the money

An unpermitted basement apartment is worth less at sale, is difficult to insure honestly, and leaves you exposed if a tenant is hurt. It also gives a tenant leverage in any dispute. The gap between the informal version and the permitted version is smaller than most people assume, and everything above is the reason the permitted one costs what it costs.

What the declared value excludes

Design work, the permit fee, appliances, and finishing to rentable standard. It also excludes any underpinning, which is filed as its own permit.

Three questions before you sign

• What is my finished ceiling height, measured today? Ask before anything else. It determines whether this is a $35,000 project or a $120,000 one.
• Is the egress window included, including the well and the excavation? Get it itemised.
• Who signs off the fire separation? There should be an inspection, and you should see it pass.

Note on the data: this job has the smallest sample of the seven on this site. It clears our publication threshold, but treat the range as slightly softer than the others.