Code should be about fire safety for the fire department if it burns. if you can't build on the lot then it needs to be because of something there - or if they are planning to build it (a new utility) then they need to rebuy the easement every 10 years until they do. Height is limited only by airport flight lines.
everything else is none of your business. (Okay, I might have missed something but it is on those lines)
Height (number of units, really) is limited mainly by the bandwidth of the roads, water mains, and sewers in the area. These are things that are expensive, very expensive to expand. Of course in practice height is firstly limited by zoning to protect existing properties' owners, but you can't ignore the infrastructure needed for larger buildings.
everything else is none of your business. (Okay, I might have missed something but it is on those lines)