Just go with one of the big ones ....you pay a little more for the peace of mind............My new shed is whats called here rolled purlin frame ,colour gal sheet cladding..........Came as a kit ,but with all planning and design approvals ..........this is where a big supplier is advantaged ......they are submitting applications all the time ,and councils just wave them through planning approval................A big supplier will also tell you straight up if your location /council is likely to be problems with planning ..................My shed was way over the size and cost limit for owner erected ,and code required a licensed builder ........the shed co is a licensed builder ,and so I could put up the shed myself using their licence...........just a matter of a peg out front with a small sign and their licence no.