My uncle lives in an area where a new house must be on a minimum sized lot of 1 acre. A nearby area requires 5 acres for a new house! I'd never heard of those kinds of restrictions before.
We have that here in Portland, it's the urban growth boundry. To control the growth of sprawling suburbs and encourage higher density construction, outside the boundary you cannot get sewer service and so must build on a 1+ acre lot with a septic field. It works pretty well for us. I'm sitting less than 100 feet from our boundary right now (on the inside), and just the other side is acres and acres of open farmland.
I live in Seattle and while I am aware that not everyone lives in a similar environment the concept of a minimum 5 acre lot staggers me. I consider myself lucky to have 600 square feet.
What kind of area has these rules and who sets them? To me a lot with 5 acres is officially "the country" where I would expect very little to zero regulation of what you can build.
For example, here is a zoning map for New Canaan, Connecticut a suburb of New York in south western Connecticut. About a 25% of the town is zoned for 4 acre lots, 50% for two acre lots, and 25% for smaller lots (just my estimates from looking at the map).
He's in Western Washington, but not too close to Seattle. To him it's "in the country" but it's right next to town. I live in a rural place, "in the country" means something entirely different to me.
My definition of "country" is having a yard big enough to throw a tennis ball for your dog as hard as you can, as far as you can, within your property, and not have it hit something. Just any linear stretch of maybe 150'. People in cities very rarely have that, unless it's some kind of billionaire hilltop mansion type situation. Many people can't even own a pet because their apartment disallows it.
Same thing would apply to shooting a gun on your property. If you can do it without the cops coming, you live in "the country" as far as I'm concerned.