If the unit is fully permitted you can actually request a NEW address for it and rent it for much higher value specially if it's in a great school district.
This will give you a good idea of what is typically required for an accessory building or a second dwelling unit. Especially if you plan on renting it out be sure it has been built with the proper permits.
San Jose real estate information at http://julianalee.com/san-jose.htm
Top 2 agent nationwide at Keller Williams Realty, the nations largest
Over 20 years experience
Over 1,000 homes sold in Santa Clara and San Mateo Counties
If you like this answer or if it was useful to you, a quick click on the green 'thumbs up' would be appreciated.
"Helping People Make Smart Real Estate Decisions since 1980"
(651) 457-HOME (4663)
Keller Williams Realty