However, I do expect the codes to relax overtime, so my architect designed a large walk in closet for one of the bedrooms that could be potentially convert into a bathroom in the event that Santa Clara allows a 2nd bathroom for ADUs in the future.

@John Schulz - I think the best person to start with is an architect. 

Beyond that, I'm assuming he'll be using a GC and/or architect?

*Disclaimer: I am not an architect or zoning expert, but rather a general contractor and developer who has worked on many projects in RS3 zoning and done a tireless amount of research on zoning rules & regulations. 

Has an architect done the plans? 

I then had to have it inspected by a commercial architect (one of the wife's patients), a certified commercial building inspector, (old friend of ours), for all electrical & plumbing compliance & then the fire chief, (also one of the wife's patients).It was a LOT of work & after attending classes to design & install the systems & them showing the effects of such systems on fire prevention I certainly appreciate the dire need for these systems. 

I am an architect and have always wanted to finance and build my own work.

With all that said he likes the idea of selling to me, a young architect, based out of New Haven.

Collaboration with Experts: I assembled a team of experienced contractors, structural engineers, and architects to devise a comprehensive repair plan.

I am thinking I need to speak to an architect prior to being able to do the pro forma.