In modern skyscrapers, the exterior walls are no longer load-bearing; rather they add to the weight that must be borne by the core of the building. The margina

In modern skyscrapers, the exterior walls are no longer load-bearing; rather they add to the weight that must be borne by the core of the building. The marginal cost of adding ornamented granite and brick on the exterior of a modern skyscraper would be much higher than the cost of adding ornamentation to a building whose structural design already calls for a heavy material for the walls.