What governs a Saskatoon rental instead is the Residential Tenancies Act, 2006, which sets notice periods and process for rent increases but does not cap how much an increase can be, and it applies the same way to a brand-new secondary suite as it does to a decades-old apartment.
A landlord adding a new suite in Saskatoon can set the initial rent at whatever the market supports and adjust it later, provided the required written notice is given under the Act. There is no separate registration or reporting requirement tied to the unit being new.
The bigger factor for a new suite's rent potential is whether it is permitted, not whether some stabilization rule applies to it. Get your hand-reviewed valuation from Joel Dyck.