You need enough space to stand up, stick your arms out, and move around. Considering the average human wingspan is 5' 9" for men, add another foot and change on each side for a safety factor so you don't smack things if you lean a bit, and you end up needing a playing space that's an 8' diameter cylinder, and that's just for seated/standing experiences, not room-scale. This 8' cylinder also needs to be next to a computer, or you need to run a lot of cables. I live in a 3 story row house and the only space I have with enough room is my kitchen, anywhere else in the house and I'd end up hitting something.