I have a Standing area that's tiny only about 1.2m by 1.5m and it seems fine for the games i play. Basically i have the area in front of my PC Desk when i move the chair out of the way. It's not ideal but it works.
I have my lighthouses up on decorator's stands with camera grips as they take up less space than a tripod so i won't kick them and i don't have any shelves to put them on anyway. I have these but others are available
Wolfcraft Decorator Stands - Amazon UK
According to the Vive FAQ:
For room scale VR you will need a minimum of 2 meters by 1.5 meters of free space (6.5ft x 5ft), and the maximum distance between base stations is 5 meters (16ft).
In addition to room scale VR, Vive supports seated and standing VR experiences, both of which do not have a minimum space requirement.
Valve Vive FAQ