Rethinking density limitations like building height, parking requirements, and ADU permitting would be more impactful. 

Timing your permits and applications might be tricky.

Duplex have different zoning that may permit additional units.

Will I still be permitted to file an affidavit of memorandum EVEN THOUGH my closing date has now come and gone and I am technically in breach of contract?

I have done everything the right way, the ethical way, treating people with honesty and respect.. treating the market and the process with respect (not cutting any corners, permits, etc) and it seems like I have been beaten down at every turn and now I am at risk of losing everything I have worked hard for years to obtain. 

If long-term, rebuilding the home could offer substantial future gains, but keep the high construction costs and California’s permitting process in mind.Mariposa homeThis emotional project has potential as a vacation rental due to its location.

Plus they are just lovely to work with.And yes a 15 year veteran in both residential and commercial construction, we pull permits. 

In Los Angeles at least I see a lot of flips with no permits.

A lot of homes have had bathroom and kitchen modifications without permits.

DDidn't even know Philadelphia had a licensing requirement looks like they do:https://www.phila.gov/services/permits-violations-licenses/g...Doesn't seem like the barrier to entry.