Apparently if I want to build something less than 120 square feet, I can do whatever I want, but if it's bigger I need to do some structural engineering to show my structure can handle wind shear, uplift, seismic activity, etc—even it's just a 200 square foot chicken coop!<p>Since it's a bit silly to pay someone to do that for a humble chicken coop, and since learning how to do it sounds fun: have any of you developed plans for your own small structure and gotten them approved by your city? I'm in Los Angeles County.
Go down and talk to the people who will be approving (or not approving) your plans.<p>Maybe in theory, you can design it yourself, in practice it may be painful and frustrating (or it may be easy as pie but "Los Angeles" makes me a bit doubtful).<p>To put it another way, you can design and build your own bicycle but their might be undesirable consequences of a lack of expertise/experience.<p>Disclaimer, I have a background in construction and architecture and once worked in a building department and before that a planning department. Good luck.