You as a property owner can pay to get your lot lines surveyed, but building cinder block or concrete walls between lots is generally not done due to cost, aest

You as a property owner can pay to get your lot lines surveyed, but building cinder block or concrete walls between lots is generally not done due to cost, aesthetics since its considered an eyesore, doesn't add tangible value for the current owners and can hamper shared use items like the laundry pole you mentioned. I wouldn't want to live on a property blighted by a cinder block wall. With the risk of earthquakes here on the West Coast you would want a good foundation and rebar/concrete reinforcement for such a wall as well.