Because this way with the same addition you are not only getting the value back in square footage, but also the value in gaining a bedroom and bathroom.

Or there is a reason why "agent-measured" is an option in FMLS for square footage.

Depending on all the variables (builder, square footage, finishes etc), I believe the homes would sell anywhere between 300-450k.  

Adding an ADU is a great way to add square footage, but you might run into appraisal issues and it adds complications.

Also, I'd emphasize location and square footage over units.

The ability to turn an SFR into a 3-plex by adding an ADU and a JADU (junior adu [garage conversion]) means we can maximize cashflow and get a huge ROI by also adding square footage and adding overall value to the property.

Step #1GET CASH BUYERSYou can do this by advertising, going to local real estate investment meetings/clubs, putting up bandit signs(if they are legal in your area), using craigslist, going to tax sales or sheriff's sales(all cash buyers), building a website and driving traffic to it, or you can pay for access to a list(just google "cash buyer's list).Make sure that when the cash buyers call you, that you find out what types of properties they want, how many beds/baths, square footage, what area they want properties in, what price range, if they are buying with all cash, how quickly they can close, etc.

My dad who is a local builder/flipper in the greater Eastside area has built this home for $150 a square foot https://www.redfin.com/WA/Renton/1408-N-34th-St-98056/home/408742I would say it is possible in our market but as you mentioned, very dependent on square footage, finishes etc.

If you are going to owner occupy a house and add value, through renovation or adding footage, you will want to use conventional financing and do it up over time. 

Question being, is there ANY LEGAL REQUIREMENT or Minimum square footage or area needed in order to rent that studio to section 8?