As the laws both from a taxation point and landlords rights are very different per province and obviously different from the US market it’s really difficult to find a good tax accountant who a) is used to working with investors and b) is allowed to practice in both provinces and c) understand the “gottya’s” and can guide you. 

Separating these businesses is advantageous from a taxation standpoint (S-corp for salary/dividend splits for FICA-based income) and a risk standpoint ("flips" are liability centers that should be separated from "rentals").