Can anyone tell me when is a permit required?

Greetings all,I have a background in construction engineering and management and I want to take on a role as a GC/Developer/Planner for new construction of a pre-fabricated home property.I'm planning on building multi-unit structures for rent in an urban lot, (I will have to get this lot re-zoned) but for the process of construction, I'm trying to determine which permits I absolutely need to obtain, and which inspections I need to conduct, and how much all of this is going to cost.In other words, I'm having difficulty in determining fact from fiction when it comes to inspections and permits, and distinguishing which ones I absolutely must obtain, and which ones are just "good to have."

The current investor has a general contractor who has open permits for the entire project, so apparently I would take that over. 

My problem is that land and permitting in my immediate area is priced so high that it isn't feasible.

Here is the link for the map https://newbraunfels.maps.arcg...A 2023 goal is to purchase an STR out of state - preferably Phoenix Metro or Denver Metro - and in an area where I can get it permitted. 

Any issues with permitting / conversion of the 4th BR?

Hello,Total purchase was $602,000 plus closing costs (appx: $8,000)The cost for the ADU was $265,000  ( It is a 3 bedroom 3 bath with a kitchen and 2 wet bars which I rent separately , including Plans and permits (Appx: $ 15,000)This was my first property when I did this, I paid for the ADU with lines of credits and credit cards and than refinanced and paid them off.I noticed you said it sounds kind of high, are you located in the Los Angeles area ?

My grandparents have a couple condos on Miramar Beach, I try to make it out once a year for some family time and vacation when work permits.

If the tenant wants to use it as another bedroom, you'd better make sure that's permitted/inspected, and there are two means of egress from the basement.That's a major health/safety issue not to be ignored.

It took a long time to receive the demolition permit.