If you look at new houses (one family) even Mcmansions they all seem to be stick built and worry about siding, shingles for roof etc. but even small (under 5 story) apartment buildings are differently constructed using (for example) re-enforced concrete floors and steel girders for the frame. The roofs are probably stainless steel. Why the differences?
In a new apartment building how do you install DWV? I don't see drilling 4.5 inch holes all over the place for toilets etc. You'd have to drill through 8 inches of concrete and rebar. Maybe its advance planning by the architect but there must be rules he follows. Why not use the same for a house? Where are all the products for this type of building? Why aren't the same concepts used for repairs/additions to existing homes?
Just wondering...