If the diagram is to scale, then from the specs it's suggesting a room of about 4m x 4m.

Looking at their other product the "Studio Suite" that one's diagram and specs suggest a room about 6m x 3.5m.

(Both are larger than my largest room.)

On their marketing page, they target landlords not tenants, with the suggestion that landlords should buy these and will then be able to charge higher rent.

The specs say it's 78"x75" (98"x75" for large version) when open. How much space you want beyond that is up to you I presume as it depends on your door position and layout of rest of room. If you just have a couch then that's probably a couple feet around for entrance and 4 feet for the couch. So roughly you'd want a 10' x 11' room.