Do building codes & zoning play a role in this? I've seen some crazy structures in the US, including a castle in Northern Idaho, but they tend to be in places

Do building codes & zoning play a role in this? I've seen some crazy structures in the US, including a castle in Northern Idaho, but they tend to be in places with lax building codes (or lax building code enforcement) no HOAs and no urban zoning. Just in the start of the article they mention a few things that we be hard to build legally in the US: handrail-less stairs, rail-less balconies, windowless rooms & houses.