My subdivision has subdivision covenants regarding materials of construction, setbacks, outbuildings, mobile homes etc. It does not and has never had a HOA. The covenants were put in place by the subdivision developer and are part of the deed. So the existence of a HOA is not a requirement for restrictions.
One of my neighbors wanted to build a smaller house than the restriction (by only a couple of hundred square feet.) They made a petition and got X number of property owners in the subdivision to sign it. I don't know what entity approved the petition, nor what number of % of homeowners had to sign it. They had to have it processed before the building permit.
I'm sure laws about this sort of thing are highly variable. My advice is to talk to an attorney, and/or the codes enforcement entity. If you do have such a petition, go around to the people with the stuff in their driveways, and their neighbors, and get it signed first.
That neighbor sounds like a PITA and I would not care to live across the street from her.
