saxitoxin wrote: Should I risk building it and just cross my fingers the county doesn't find out or should I leave it unplumbed? The thing is, I want to use it as a crash pad for guests when I have pool parties. That means they'd have to come into the house to use the bathroom if I didn't plumb it.
You can risk it, but note that this is a rather well-known house and it is unlikely it will escape notice... unless maybe you are one of those with the 12' hedges around your property (in which case folks may call in just to have an excuse to "lookeee".
Of course, being CA.. have you looked into composting toilets or something similar? It sounds gross, but properly constructed... isn't. I am not sure UCSB is the greatest resource, but I can find out for you if you wish.

(see, I don't hold grudges against people with whom I politically disagree).
Did a quickie search, LOTS of info out there.
Here are a couple regarding legalities:
http://www.ehow.com/list_7196739_califo ... ilets.htmland
http://www.composttoilets.net/stateregs.htmand here are a couple that go more into the concept, why it works, etc.
http://inspectapedia.com/septic/altcompost.htmhttp://www.ideamarketers.com/?Compostin ... om=PROFILEPS you could also hook up to the septic, but have this composting system to satisfy regulators.