and to modify, without problems, the interior layout of the homes. Constructive and decorative items Facade The facade is composed of large blocks of limestone from the Garraf Massif on the first floor and from the Villefranche quarry for the higher levels. The blocks were cut to follow the plot of the projection of the model, then raised to their location and adjusted to align in a continuous curve to the pieces around them. Viewed from the outside the building has three parts: the main body of the six-storey blocks with winding stone floors, two floors set a block back with a different curve, similar to waves, a smoother texture and whiter color, and with small holes that look like embrasures, and finally the body of the roof. Gaudí's original facade had some of its lower-level ironwork removed. In 1928, the tailor Mosella opened the first store in La Pedrera, and he eliminated the bars. This did not concern anyone, because in the middle of twentieth century, wrought ironwork had little importance. The ironwork was lost until a few years later, when Americans donated one of them to the MoMa, where it is on display. With restoration initiatives launched in 1987, the facade was rejoined to some pieces of stone that had fallen. In order to respect the fidelity of the original, material was obtained from the Villefranche quarry, even though by then it was no longer operating. Hall and courtyards The building uses a completely original solution to solve the issue of a lobby being too closed and dark. Its open and airy courtyards provide a place of transit and are directly visible to those accessing the building. There are two patios on the side of the Passeig de Gracia and of the street Provence. Patios Patios, structurally, are key as supporting loads of interior facades. The floor of the courtyard is supported by pillars of cast iron. In the courtyard, there are traditional elliptical beams and girders but Gaudí applied an ingenious solution of using two concentric cylindrical beams with stretched radial beams, like the spokes of a bicycle. They form a point outside of the beam to two points above and below, making the function of the central girder a keystone and working in tension and compression simultaneously. This supported structure is twelve feet in diameter and is considered "the soul of the building" with a clear