Build Your Own House

Gday peoples, ok, im a first timer at this reno home owner thing,, plans are done, planning approval done, now for the builders license.. here's the firs curly one. I read that a owner builder in WA cannot build a garage seperate from thh house??? i am, or want to!... 2, you cant build more than two single story structures, or one double story, i want to build two seperate two story structures....one is a bathroom with bedroom on top, the other is a garage with art studio on top...... question, how do i go about this ( aka) get around this legally?? It ana ddition to a 1913 lime stone cottage. I will be using limes tone blocks tin and timber.... also, has anyone got tips for applying for a owner builder license, ie, the do's and donts....
Thanks peoples, i would much appreciate your input..