He used modern techniques and materials, including iron construction (a pioneering solution also used in other Napoleon III buildings, including the Bibliothèque Nationale and Les Halles).
Garnier did not leave spaces undecorated. He used polychrome (a variety of colors) for a theatrical effect, many varieties of marble and stone, porphyry, and gilded bronze.
Seventeen different types of materials were used on the opera house’s façade arranged in elaborate, multicolored friezes, columns, and statues, many of which depict deities from Greek mythology. Fourteen painters, mosaic artists, and seventy-three sculptors participated in its creation.
