Not just that, but you probably have to get permission from zoning boards, planning commissions, and others, use contractors that are "licensed" to do that work in that city. I bet the local politicians have made it very difficult to make any business work in that city.
Chicago was the same . . . I grew up there, and my Dad and I did a lot of work on our own house that was probably not allowed, as we weren't licensed union plumbers/electricians/plasterers/carpenters/whatever.
And there was no such thing as a "permit" so long as it wasn't visible from outside . . .