We understand that there are building codes that we have to follow and permits that we have to get from the building department.Does anyone know if we need something from the planning department?

Forget about the LLC and asset protection classes, be good, have insurance (an umbrella when you get rich) and abide health and safety codes you will be fine.

They will examine the zoning code and advise as to how big your structure could be to comply with all relevant ordinances.

@Remington Lyman so far I’ve narrowed it down to A and B zip codes (defined in a document from Zeke at Reafco), and in the near future I’d like to narrow that down from around 20 zips to 5.

Yes, both condos are also in the same zip code! 

I'm Brian Silvia -- by day I write & ship code, but by night I'm either doing Crossfit with my wife, or working with her to get spun up on real estate investing.

If you are an NAR member, it is also a requirement per the Code of Ethics. 

Because of Code differences, you will most likely also be looking at tearing out the basement ceiling to install a fire retardent barrier between the units, as well as other code enforcements.

For example, that no more than 25% of the existing SFR may be demolished/altered to make way for say an access driveway easement for the new rear flag lot.

It did not pass the township codes also.