"… usually through a door, though it may vary by space."

But in all seriousness… awesomesaucenness if you want to start one of your own:

Hackerspace Design Patterns: http://jaromil.dyne.org/journal/documents/Hacker-Space-Desig...

or here:

http://hackerspaces.org/wiki/Design_Patterns

and if you're in Vancouver: stop by http://vancouver.hackspace.ca sometime

xoxo!