I'm interested if you spoke with an architect for your Triplex to quadplex conversion?

My architect/contractor wouldn't give us a quote yet unless we meet the county and review the violations. 

Next, assuming you have already confirmed that you're in an ADU 'pilot' area, I'd check with an architect about the FAR and zoning of your property.

Stage payments kicked-in based on architect's certificates during the construction process.

Meet with contractor or architect to discuss floor plan, where plumbing will go etc.

Construction cost estimate includes land, permits, architect/engineering fees, GC fees, landscaping, and the finished building itself.

I am the architect behind a historical piece of legislation in California that will, hopefully, correct the economic wealth gap that makes it a challenge for some to create the scenarios that lead to economic freedom.

You need a skilled team - attorneys, architects, designers, and accountants - to effectively navigate the historical renovation.

Regarding your comment about about "Colleges teach ZERO of use in the real world", I'm guessing your lawyer, doctor, accountant, architect, structural engineer, teachers who teach your children, etc wasted their time and money in college.

However, you can hire a drafter or architect (more expensive) to draw up "as builts" that can be used.