In Australia at least, there's a limit to the sort of shit you can actually do to your house legally, before insurance or other mishap avoidance things leave you in the lurch should something go wrong - even if it isn't your fault.
It is similar here - but for some things, as long as you have a professional inspector sign-off on it, it is fine. Electrical and plumbing are tradie only though.
Yet the Bunnings car parks are some of the busiest places on Earth. (Bunnings are our monopolistic hardware stores) - and they're not exactly filled with trade vehicles.
Yeah, I don't get it. Maybe it is older people only? There for the sausage sizzle perhaps!