I am looking at buying a multi-unit building, which is currently occupied, at auction.

What do you recommend as far as evicting the tenants, or can I keep them if I notify them of transfer of ownership? I have always been told to ensure the property is vacant, but in this case it makes sense to keep them, if they are happy to stay and keep paying.

Any advice?

Good questions. Some recent legislative changes you may want to review regarding tenants and foreclosure are included in California Civ. Proc. Code 1161a, 1161b, pl 111-22. Also read Cal Civ Code 1946.1. Also, be sure to check your local ordinances which may impose even more restrictive requirements.