Check out United Dwelling as well.

Nationwide the ratio of dwellings is 2/3rds owner occupied and 1/3rd non-owner occupied. 

They (1) forbade any use deemed to be commercial in nature, including down to the level of "renting even one room", they then (2) forbade any residential use of any building other than the main dwelling unit, and so on.

In regards to financing, I’m just unsure if FHA has restrictions against Accessory Dwelling Units (ADU) attached to an FHA financed 4plex.

1117-19.1 Dwelling units: Every dwelling unit shall contain a minimum gross floor area of not less than 150 square feet for the first occupant, and 100 square feet for each additional occupant.

Depending on location but infill its normallyCondos, stack towns to rowtowns Suburbs are residential subdivisionsMostly end user dwelling in Toronto area..Where you at?

Or maybe the home of your dreams with an additional dwelling unit that you can rent out to soften the mortgage.It's all dependent on what you're comfortable with vs. how little of your mortgage you're willing to pay.

With 60 days notice, you may offer to transport them to another dwelling of their choice. 

The state requires at least one parking spot per dwelling unit.

IN DETERMINING WHETHER ALL OR PART OF THE RENT DUE AND OWING IS THE RESULT OF AN UNCONSCIONABLE RENT INCREASE, IT SHALL BE A REBUTTABLE PRESUMPTION THAT THE RENT FOR A DWELLING NOT PROTECTED BY RENT REGULATION IS UNCONSCIONABLE IF SAID RENT HAS BEEN INCREASED IN ANY CALENDAR YEAR BY A PERCENTAGE EXCEEDING ONE AND ONE-HALF TIMES THE ANNUAL PERCENTAGE CHANGE IN THE CONSUMER PRICE INDEX FOR THE REGION IN WHICH THE HOUSING ACCOMMODATION IS LOCATED, AS ESTABLISHED THE AUGUST PRECEDING THE CALENDAR YEAR IN QUESTION;"  This sounds like you can still increase rent but it will based on change in CPI for the area.