Casa Mila Architecture: Style, Curtain Wall, and Construction

Constructed in 1912 for Roser Segimon and Pere Milà, Antoni Gaudi’s Casa Mila appears more organic than artificial—as if it had been carved out straight from the ground.

Also known as La Pedrera, the Modernista movement influenced the building, which is Spain’s version of Art Nouveau.

Casa Mila was a controversial building of its time that contributed significantly to Spain’s modernist movement.

During the design of the building, Gaudi intentionally drew on organic forms that were influenced by natural patterns.

Antoni Gaudi was a genius regarding structure and form, and Casa Mila-La Pedrera is a living example.

This article will help you understand the La Pedrera architecture in detail.

Casa Mila Gaudi architecture plan

This building has nine floors: basement, ground floor, mezzanine, main floor, four upper floors, and attic.

Here’s a table depicting their functions:

Ground floorThe Garage
Main floorThe Milas
Upper floorFor rental purposes
RoofThe famous terrace structure

Casa Mila architecture style

Gaudí was a master of design and used his skills to create a beautiful and innovative building.

One of the most exciting things about the Casa Milà Gaudi architecture is its structure. 

The stone facade of the building is not load-bearing, meaning that it does not support the weight of the building. 

Instead, steel beams support the facade. This allowed Gaudí to design the facade without any constraints, which is why the building has many unique curves.

This allowed Gaudi to design the attraction without structural constraints, which helped his vision of the curved facade.

Moreover, the structure holding up the roof allows organic geometry to help the overall infrastructure.

La Padrera’s spine-rib structure creates a varied topography from its 270 parabolic brick arches of different sizes.

Technically, the overall facade can be understood in three sections:

  • Street Facade: Spans over the ground floor
  • Main Facade: Spans over the main and upper floors
  • Roof Structure: Supports the roof gardens and includes the attic.

Made primarily of limestone, the curve of the main facade has the weight and texture of organic geometry.

Above it is the curvy mass where modernist humanistic sculptures sit on a curved group that rises over it.

The flowing and curving structure adds to the unique dynamics of the building.

To learn more about its peculiar construction, keep reading!

Did you know that you can visit Casa Mila and Casa Batllo together?

The combo ticket allows you to explore the two houses of Gaudi for the price of one.

Casa Mila construction

Here’s a breakdown of Casa Mila’s construction:


Casa Mila consists of two blocks of apartments with entrances and vehicle garages.

Each apartment is structured around two large, interconnected courtyards whose ramps connect them to the garages.

Curtain Wall

La Pedrera’s facade is not a structural element but a curtain wall built to give the building a unique look.

Metal components connect six thousand blocks of stones, making the large windows in the front possible.

There are three types of stone used in the making of the facade:

  • Limestone from the Garraf: used in the lower parts and other structural elements
  • Stone from Vilafranca del Penedès: used in the bulk of the facade
  • Limestone from Ulldecona: used in some fantastic features, like the frames of the windows

The Ironwork

At Casa Milà, he used scrap iron sheets, bars, and chains to create the complex wrought iron grilles of the 32 balconies.

This was a very unusual way to build something, but it was also very effective.

The grilles are both beautiful and functional, and they complement the architecture of the building perfectly.

Gaudí’s use of scrap metal was ahead of its time. 

He was one of the first artists to use scrap metal to create abstract sculptures. His work inspired many other artists in the 20th century.

If you want to see this architectural beauty at its best, read our articles on the best time to avoid crowds at Casa Mila.

Entrance doors

Antoni Gaudi’s sole purpose with the entry doors was to facilitate entrance and exit for both vehicles and people.

The unusual structure of the entrance doors was a specimen of Gaudi’s genius in the face of crisis.

As large sheets of glass were unavailable then, Antoni fitted a series of irregularly shaped panes based on animals and plants.

He created a small area of protective pieces of glass at the lower part, where they were at a greater risk of being broken.

Also, he added luminous pieces at the top for an artistic touch.

The brilliant structure simultaneously acts as a grille and a door for vehicles and people on foot.

It can be opened in the middle for cars to pass, and visitors can walk through the side parts.


Antoni Gaudi wasn’t considered brilliant for no reason, as he anticipated the need for modernization in the 20th century.

He built the garage’s basement for coaches and cars, the first in a residential building.

Gaudi used slender iron columns and a unique metal structure similar to a bicycle wheel to support the courtyard floor.

Iron helped him reduce his build volume and gain some maneuvering space.

Ironwork in the Basement

Antoni Gaudi, the architect of La Pedrera, originally designed the iron grilles for the basement windows.

These grilles were mass-produced because they were cheaper, but 29 were removed when the basement coal stores were converted into commercial premises.

Today, you can find four iron grilles in two museums, one at the MOMA in New York and the other three at the Gaudi House Museum.

At Casa Mila, you can still see two grilles at the Passeig de Gràcia entrance and a copy at the Carrer de Provença façade.


The Courtyards are another remarkable addition to Casa Mila’s Barcelona architecture.

Gaudi chose an innovative way to make ventilation shafts to build the courtyards, which was new in the previous building type.

He attached small ventilation shafts and built two courtyards to improve lighting and ventilation in all 16 apartments.

Wall Painting: Entrance

Casa Mila’s entrance halls have paintings resembling curtains with mythological themes. 

The symbolist painter Aleix Clapés (1850–1921) was commissioned to work on the pictorial decoration of Casa Mila.

One of the paintings in the Passeig de Gràcia entrance hall is about the love of Vertumnus, the god of seasons, and Pomona, the goddess of fruits and gardens.

The paintings in the Carrer de Provença entrance hall do not have precise edges and borders, so you can interpret them as you like.

For example, you might see the cardinal sin of wrath on one side and the horses of the Trojan War and the Adventures of Telemachus series on the other.

The Iliad and the Odyssey inspired the paintings.

One difference between the original paintings and these reproductions is the trompe-l’œil

The pictorial decorations create the beautiful illusion that we go up and down a staircase alongside a garden.

To achieve this, Clapés painted columns similar to the other columns situated at the end of the steps.

Casa Mila Construction of Apartments

One of the most brilliant solutions at Casa Mila is the pillar made of stones, brick, or iron.

This eliminated the need for overbearing walls and allowed Gaudi to use the interior space of the apartment floors freely.

Distribution of the apartments

The most notable characteristics of the apartments are their irregular geometry and well-defined internal organization.

This distribution was intended to make the most of the south-facing main facade of La Pedrera.

The lifts at the apartments provide direct access to the entrances of the flats on each floor.

Each floor has four apartments, so each flat has a section of the main facade.

La Pedrera Architecture of Ceilings

The ceiling at Casa Mila has variations; some consist of high relief, inscriptions, and even poems.

All of them have one aim: to continue the undulating rhythms of the facade.

Casa Mila Gaudi’s architectural style expresses the spontaneity of matter and forces in nature.

But simultaneously, they combine culture and tradition in the context of modernism.

The decorative motifs on the ceiling have a new plastic art quality despite being born out of traditional ornamental forms.

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An interesting Casa Mila architecture fact is that Roser Segimon disliked the decor and furnishing Gaudi did for her apartment.

So, after the designer died, she changed the entire decor into a more conventional style.

This change ultimately resulted in the destruction of ceilings up to 532.50 square meters.

The rooms affected were the ballroom, hall, office, drawing room, dining room, bedroom, and corridor.

In addition to this, the parquet flooring and blinds were removed, and 20 doors in total were replaced.

The Decorative Arts

Gaudi employed the same methodology to design a vast building and a small object.

He believed that everything should have some function for humankind.

For knobs and handles, he used simple shapes ideally suited to the joints of the hands, making them easy to use.

The Pedrera Apartment

During the day tour, you can see the apartment that displays the building from two perspectives: its unique architecture and habituality.

The apartment on the fourth floor above Milas’s residence gives us an insight into the bourgeois lifestyle of the 20th century.

The Attic

Gaudi constructed the attic on the floor slab of the top story.

He used 270 catenary arches made of brick to prevent adding weight to the building to support the roof.

The catenary was a helpful addition, as the arch is light, easy to build, and can support itself without buttressing.

Initially, the attic housed the building’s laundry room and acted as an insulating air chamber.

After purchasing the Casa Mila tickets, you can spot Gaudi’s exhibition, an incredible display devoted to his life and work.

Roof Terrace

The roof of Casa Mila’s architecture proves three aspects of Gaudi’s brilliance: insulation, lighting, and ventilation.

On the roof, visitors will find the fantastic and tremendous functionality of the building: stairwells, ventilation towers, and chimneys.


Gaudí used curved forms in the stairwells to make the building feel softer and less imposing. 

Out of the six stairwells, only four are covered in trencadis, a type of mosaic made from recycled and monochrome stones. 

The other two stairwells are made of marble and ceramic, and the others are plastered with lime.


The chimneys on Casa Milà are freestanding, and some are joined in groups of three or four. 

They rotate on their axes, following an exterior and interior line that corresponds to the aerodynamic displacement of smoke coming from them. 

This means the chimneys are designed to help the smoke escape from the building quickly and efficiently.

Casa Mila history in a nutshell

  • 1905: Pere Milà and his wife, Rosario Segimón, buy a house on Passeig de Gràcia and commission Antoni Gaudí to build a new apartment building.
  • 1906: Construction begins.
  • 1907: The Barcelona City Council complains that the façade is too big and asks the owners to pay a fine or demolish the attic and rooftop.
  • 1909–1910: Casa Milà receives a building permit after the Eixample Commission declares it a monument.
  • 1911: The Barcelona City Council grants occupancy permission for the main floor.
  • 1912: Gaudí declares that the construction is over and occupants can move in.
  • 1929: The first retail establishment opens on the Casa Milà grounds.
  • 1936: The United Socialist Party of Catalonia seizes Casa Milà and uses it as a government building during the Spanish Civil War.
  • 1946: Rosario Segimón sells Casa Milà to a real estate company. She continued to live on the main floor until she died in 1964.
  • 1953: The real estate company converts the attic into 13 flats and the first floor of Carrer de Provença into four small apartments.
  • 1962: Casa Milà is included in the Artistic Heritage list by the Spanish government.
  • 1969: Casa Milà is registered as a historical and artistic monument of national interest.
  • 1984: UNESCO lists Casa Milà as a World Heritage Site.
  • 1996: Casa Milà is restored and handed over to Barcelona.
  • 2002: Casa Milà hosts the Gaudí Art and Design event to mark the International Gaudí Year.
  • 2012: The hundredth anniversary of Casa Milà’s construction is commemorated with cultural and artistic events.


What are the architectural features of Casa Mila?

Casa Mila’s undulating facade and the surrealist sculptural roof are some of the artistic features of the attraction.

Roser Segimon and Pere Milà built a flawless building with nine floors. 

Its curvaceous facade with lightweight curtain walls makes it one of Antoni Gaudi’s best works.

What type of architecture is Casa Milà?

Casa Mila has modernism as its architectural style.

The style, also known as Catalan Modernism, was one of its kind in the 20th century.

Stone Quarry, or La Pedrera, was named by visitors because it appears to be carved from stone.

Who is the architect of Casa Milà?

Antoni Gaudi and Josep Maria Jujol were the architects of Casa Mila.

Roser Segimon and Pere Milà commissioned them to build the residence.

What is unique about Casa Milà?

It is considered the best work by Antoni Gaudi due to its constructional and functional innovations.

It is also known for its ornamental and decorative forms, which broke the architectural stereotypes of its day.

Is Casa Milà Art Nouveau?

Yes, Casa Mila was one of Gaudi’s most remarkable Art Nouveau buildings.

For Antoni, Casa Mila’s architectural style represented a fast approach to a building in Barcelona. 

Featured Image: Tripadvisor.in

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