Complex sentence: Traditional buildings supported their internal floors through their walls, but the taller the building, the thicker the walls had to become, particularly at the base: buildings of any substantial height rapidly saw their lower floors eaten up by brick or masonry.
Split into simpler sentences: Traditional buildings supported their internal floors through their walls, but the taller the building, the thicker the walls had to become, particularly at the base. A building of any substantial height rapidly saw their lower floors eaten up by brick or masonry.