> it costs exactly the same whether there's one house or two houses or a 4-plex at that place. In your specific example: + More cars parked on the street + M

> it costs exactly the same whether there's one house or two houses or a 4-plex at that place. In your specific example: + More cars parked on the street + More existing pipes under the asphalt to avoid or repair if you damage + More traffic on the street so you have to work more condensed hours and limit the time the street can be closed + Typically more density means less open room for moving machinery/workers/equipment Ripping out a street and running a new main is endlessly easier in the middle of a small town than it is in downtown NYC, from getting the equipment in place to doing it safely.