My rule is simple. If you can show that the property is tied to producing things either for a sole proprietorship or a family-run business (in any form), then

My rule is simple. If you can show that the property is tied to producing things either for a sole proprietorship or a family-run business (in any form), then it's exempt. I don't think the burden of proof needs to be very high. The key thing though is that mere rental businesses would not be. Land, capital, and means of production employed in production would be.