Some municipalities do not allow rooming houses and most landlords are unwilling to create legal rooming houses where you have to pass fire codes, provide exits to the outside in every unit, are limited to how many people you can house in one property, have to provide things like fire doors, etc. In most cases landlords have taken an existing home and put up drywall to create as many bedrooms as possible. Taking away any common spaces to create bedrooms and even subdividing rooms or basements to create more bedrooms. Some even put people in closets, garages with a space heater, utility rooms, cold storage areas, etc.
