A couple thoughts. I always mod the set by adding floors or widening the building. Try using the golden rule, about 1.6x the other dimension to get something that feels right. Wider and short (1.6x wide as tall) or narrow and tall (1.6x high as wide) or a multiple of that such as 3.2. A 3 story building thats 48 studs wide looks ok to me.
I prefer buildings in that 5-6 story range - right at the limit for a stairs only building.