Tenement blocks

One may easily falsely believe that tenement blocks are something that only appeared recently in history, as they are more or less staple of our cities, but the truth is that tenement blocks not too dissimilar from our own were used even in time of ancient Rome, when you have a city with growing population but limited in size by walls it is no big surprise that rulers would try to find a way to pack as many people in as little space as possible, so i suggest that tenement blocks be available when your city reaches certain population even at low technological level, naturally such things as skyscrapers are impossible without modern metalworking but regular 4-5 floor high buildings existed for a long time in form not too disimilar from that present today.

EDIT: Roman tenement blocks were called Insula, here is a wiki on them:https://en.wikipedia.org/wiki/Insula_(building)