Part of my services as an architect includes dealing with the jurisdiction. 

The owner was a designer trying to be an architect.

You can ask around to see what your county requires to get the proper permits for a construction project like that, but oftentimes they require an architect's draft of the additions and multi-stage reviews by the county of the additions in the various stages of being built, among many other things.

Obviously, you’ll have to have an architect, cicvil engineer for the design and plans creation before you can get construction bids.  

This probably isn't the best suited/easiest/most efficient tool but it's the one I know and it's free.I've heard a lot of great things about Chief Architect.

The renovation/alteration of the house does need to be designed by an engineer or architect in compliance with the Existing Building Code”.

I am an architect and real estate agent and grew up around construction - so this feels less like a job and more like a full time hobby.

Consult a structural engineer not an architect. 

I have already begun networking with a few local professionals and looking to add value to deals through my background as an IT architect & project manager. 

Then get the required consultants (possibly: surveyor, architect, lawyer).