The mechanism matters. On a house of one to four units, an appraiser working the direct comparison approach values your home against similar sales and adjusts for the suite, so the gain is whatever the market has actually paid for comparable suited homes, not the rent multiplied by a number you saw online. The income approach that capitalizes rent belongs to larger buildings, and applying it to a bungalow with a basement suite overstates the result.
Legality is what separates the two outcomes. A suite that meets zoning, fire separation, ceiling height, egress window and parking requirements can be disclosed, financed and insured normally. One that does not means a buyer inherits an enforcement risk, an insurer may decline coverage on the rented portion, and a lender will usually refuse to count the rent when qualifying. That is why two houses with identical basements sell for different money, and why a $400 to $600 inspection that documents the separation is worth ordering before you list.
There is also a tax edge worth flagging. Renting part of your home can affect the principal residence exemption on that portion, and the Canada Revenue Agency looks at the share of the property used to earn income and whether structural changes were made. Ask an accountant before you build. Then have the house valued properly, because a permitted suite is one of the improvements Joel Dyck's hand-reviewed valuation makes a seller get paid for.