Casa Milà, better known as La Pedrera due to its rocky appearance, uses multiple solutions of controlled geometry, as well as naturalist elements. It has a structure built of stone, solid brick, and metallic beams that releases the façade from load-bearing functions, which allows large amounts of light and air to enter. Even today, any partition can be knocked down without affecting the building’s structural integrity. This residential building is an exhibition of living architecture in which the undulation of stone transforms weight into airiness, solidity into movement, and the inert into the organic. What makes Casa Milà a landmark building is that its architectural expression is as timeless today as [it was] the day it was built.
— R. Scott Ziegler, founding principal, Ziegler Cooper Architects, Houston