I would say for most people, but a single family and house hack....4 or 5 bedroom if you can....and if possible be willing to give up your bedroom for the couch or garage or a camper or something else if the right situation comes along.   

May not be deductible if you use it to buy a $20k couch for your primary residence 

I think what you want to buy is 4-5 bedrooms, not 3....numbers start to work better with 4 and even better with 5 bedrooms if you can find one at the right price.Then be willing to sleep on the couch, in the garage, in a tent, in a trailer parked in the drive if you get lucky with roommate #5.Not easy....but doable.You are right on the multifamily side though...very tough from what I see to make any kind of #s work on 2-3-4.I'm guessing in most cases you won't live for free, but heavily subsidize your rent.

I posted my first apartment on Airbnb with empty furniture less pictures and offered to furnish to suit and got a 3 month booking right away at $2000/mo (I had been trying to rent it empty for two weeks for $1400 with no takers), then I went to a couple moving sales and/or shopped locally on Facebook marketplace and put in a $50 wood dining table with 6 chairs, $50 couch, $50 desk, $200 bed with frame x 2, $300 43” Roku tv x 2, $200 wifi extender, $100 of misc kitchen stuff, $100 of linens, pillows and towels.

We gave notice to vacate, spent $10,000 on renovations (painting, new floors, new hardware, re-glazing bathtubs and surrounds, new vanities and mirrors, new lighting) and about $5,000 on furnishing (beds, bedding, couches, TV’s, tables, kitchen supplies, and décor).

A nice sunroom feel- use a pull-out couch for an additional bed, but lots of pillows for decor or a comfy reading nook, a board game spot for people to sit and enjoy the sun (though all those windows) and play games, and maybe a Foose-ball table or air hockey, - make it usable for lots of different people that may stay there.

.-- Some make you go to every length of the law to get them out, making you incur expense (and for some owners) great stress (those who will face homelessness seem to do this--ie. not another rental for them, but couch surfing at a relatives, or in the street in a cardboard box in the snow and rain).Most just move out, but some will create damage to the unit (what they consider revenge) because they have that type of personality.

I can totally imagine his tenant sitting in the family room on the couch and Ehren smashing through the front window, hitting the floor, doing a roll, putting out his hand and calmly saying, "Rent's due."

Have virtually wholesaled deals all over the country from my couch, but I'm ready to get some cashflow going.

In my experience, I get a lot of fly dumping of couches and mattresses in the alleyways behind our 1-4 family buildings.