Square footage per adult in Ontario

[donksky]

I remember reading/seeing somewhere years ago where a certain number of people are allowed per xx sq. foot of interior space--that you can`t squeeze too many people in. Is this in the LTB or somewhere else? how do I know a place isn`t over-crowded? I just rented to a group of 3 students & now they want to add a fourth after just moving into my 3 bdrm as 2 of them share a bedroom as a couple, at their move-in rate of $1150+hydro. Also, BY how much should I adjust the rent if the space allows 4 & it`s not considered over-crowding in sudbury? thx