Sometimes. It depends far more on whether your specific property can carry one than on whether suites are a good idea in general.
Almost everyone starts with the layout. Start instead with whether this address can legally carry a suite at all — that answer is binary and it is free to find out.
A legal secondary suite in Calgary is a sequence, not one approval. The land use designation has to allow the suite, the City has to issue a development permit, a building permit has to be issued and the work built and inspected to that standard, safety code requirements have to be met, and the finished suite has to be registered. Requirements change over time and differ by property, so confirm the current ones with the City for your address rather than copying what a neighbour did five years ago.
Zoning first: how to find your property zoning → and what a legal suite requires →.
Do not price a suite on the renovation quote alone. Price it on the quote, the months of disruption, and the version of your home you are giving up.
A legal, registered suite widens your buyer pool at resale: it opens the property to buyers whose lender will look at the income, and to families housing a parent or an adult child. An unpermitted one does the opposite. That difference is the whole ballgame, and it is why a half-finished, unapproved version is the worst outcome of all.
See also which renovations actually add value.