It is my understanding that if you have a development or allotment or the houses are grouped in some recognized way, you can retroactively install deed restrictions and an HOA by getting a majority of the homeowners to agree to amend their deeds. I was told this by a friend whose allotment did just this in order to restrict the ability of investors to buy a property and make it an AirBnBAs to the above posts where someone was retroactively placed into a HOA, IANAL but I'm sure they could fight it in court. Just at what cost.