If you live in a place with permits, they usually have regulations which must be met to comply with current code and minimize waste. Among other things, this includes not watering hardscapes, so your sprinklers can’t water something on the other side of a sidewalk. This also means you likely need heads to be adjacent to hardscapes to avoid watering the hardscapes. Tree lawns or parkways need their own zone, as you don’t want to mix sprinkler head types, and these will be closer together because of the limited size of the parkway. A backflow preventer is generally required, and is a good idea anyway.
