General Contractor License required to Flip in California`

Hey Community, 

i have a questions specific to California and the bay Area in particular.  I recently purchased a property to flip in Berkeley, CA.  When i went to get permits for the work as an Owner-builder, the building official required me to sign a form stating i will be doing the work as an owner builder and that i could not sell it within a year.  This was alarming to me because i plan to sell right when we are finished with the construction and rehab.  I head from some people that it doesn't matter, and all i really had to do during time of sale was disclose what work i did as an owner builder.  Can someone elaborate on this?  Is a General Contractor's License required for flip projects within a year when getting a permit??  This will at least ad 10-15% into my labor costs.