La Pedrera was the last great civil work with Gaudí performed before dedicating all his time to the construction of the Sagrada Família.

The owner, Pere Milà Camps, had purchased the land and the home which manufacturer Ferre Vidal owned at the current number 92 (then number 2) of the "Paseo de Gracia" avenue. The land occupied over 1,000 square meters at the corner with Provenza street.

Pere Milà had seen the Batlló house and was enthusiastic about its beauty, so he asked Gaudí to construct a large building of rental flats on his new land. Mr. Milà's wife, Rosario Segismón was never agreeable to the architecture of her compatriot (she was from Reus) but she respected her husband's decision and lived among the guadian adornments from 1910 until 1926 when, upon the death of the architect, she transformed the entire main floor into a series of very conventional bedrooms, in the style of Louis XVI.

Gaudí planned a fantastic house with undulating, living forms. Its structure is based on wrought metallic girders and Catalan-style vaults which are supported by metallic summers on brick (mostly), ashlar or iron columns. The only structural walls pertain to the stairway. Gaudí always said that if someday the building became a hotel there would be no problem because, as it lacks weight-holding walls, the distribution of the flats may be modified by simply changing the placement of the partitions or eliminating them altogether. To hold the façade in place, undulated summers that are built into the stone and are attached to girders of various lengths. The façade construction process was a ritual; first the stone came from Garraf or Vilafranca (province of Barcelona) and were left in an area in front of the construction, and were cut according to the scale model which was made in the basement of the building. Then they were installed in the place, where they were retouched according to Gaudí's commands.

Besides the undulating façade, this work stands out because of its attic and its roof. Gaudí constructed a series of catenary arches of various heights according to the widths of the bay. These arches sustain the walls of the exterior and interior façades of the attic at the sides, and the staggered roof above. The roof is curious because it is replete with strangely shaped chimneys and ventilators.

Construction was completed between 1906, the year in which Gaudí signed the first plans, and the end of December of 1910, but they could not escape some problems with official institutions. Two years after beginning construction the city government ordered the suspension of construction because a column which was next to the Paseo exceeded the established size, occupying one meter of the sidewalk. Gaudí refused to correct it and, faced with the threat that they would cut the column, he said that if he did, he would respect their decision, but he would place an inscription where the motive could be read. One and a half years later there were problems again, but this time with some projecting cornices that also exceeded the agreed limits. On this occasion the Second Division Chief, the architect Plantada, saying that there was no problem because they were temporary faults for greater safety of passing pedestrians.

Other problems included the height of the building, which was more than four meters too high, and the total volume of construction, which was greater than the official measurement by 4,000 square meters. The City Hall ordered the attic torn down or, if not, Mr. Milà would be forced to pay a fine of 100,000 pesetas, which was almost one fifth of the cost of construction. At last, after many arguments, it was decided that the building had great artistic value and, therefore, was not subject to the city ordinances. Gaudí was so happy that he asked for a copy of the official minutes.

But the problems did not end here. Gaudí had planned a figure of the Virgin of the Rosary for the facade of La Pedrera, full of Grace and protector of the Paseo, flanked by the archangels St. Gabriel and St. Michael, but they were never installed. There are two versions that explain why: the first, stated by Bayó, construction contractor, affirms that Mr. Milà did not like the sculpture of the Virgin created by sculptor Carles Mani and it was never cast in bronze. The other version states that after the disturbances of the week of July 26-20, 1909, known as the "Setmana Tràgica" (Tragic Week), a time in which many churches in Barcelona were burned, Mr. & Mrs. Milà feared that there house could be confused with a convent or a church and preferred to eliminate any symbol of religious character. According to this version Gaudí almost abandoned the construction, which he did not do because of the conversations he had with a priest.

Today La Pedrera is property of "Fundació Catalunya-La Pedrera", which makes the roof and the attic, where one can see an exhibition on Gaudí and his works, open to the public. Some flats are privately owned and the main floor is dedicated to the exhibition hall of the Centre Cultural Caixa Catalunya (Caixa Catalunya Cultural Center).

La Pedrera was declared a World Heritage Site by UNESCO in 1984.