Turn Shed Into ADU/Tiny House in Fulton County (Atlanta) - Permit Required??

[Christine Phan]

Hi all, 

I am leaning towards purchasing a shed to turn into a ~300 sqft apartment to then eventually rent out. I may adjust to a smaller living area to avoid permits, if required. I've found articles indicating that tiny houses/adu's are allowed but it sounds like if it doesn't meet a certain sqft count, then permit is not needed? Is this actually true? I would prefer to avoid the permitting process if possible. We had to go through the permit process when building our house in Fulton County and it was not fun! 

If anyone has gone through a similar process or found resources available, please share! :) 

Thank you in advance!