Rationalism was an architectural movement of the 20th century characterized by simplicity of form based on function. Rationalist architects used industrial materials like concrete which was cheap, durable, and allowed for free floor plans. Buildings featured load-bearing pillars and curtain walls with many windows to let in light. Ornamentation was minimized in favor of straightforward forms. Rationalism aimed to accommodate new living standards through urban planning like garden cities and industrial zones. Mies van der Rohe and Le Corbusier were influential Rationalist architects who pioneered the use of steel and glass in skyscrapers and applied principles like pilotis and free facades.

1. Rationalism Revision

2. Introduction The movement known as Rationalism gathered the most important personalities of 20th century’s architecture. Their work and their theory are individual but they have in common the simplicity of the forms because each form belongs to a function.

3. Materials They use highly industrialised materials, especially concrete. Concrete advantages are: It is a cheap material, easy to adapt, incombustible, non-corrosive and that offers the possibility of building the skeleton, leaving the plan free. In addition to this, it permits the pre-manufacture in series. It can be combined with other materials such as still, glass or brick.

4. Building elements The wall is not a support any longer, and it is reduced to a light skin for closing, with a huge number of windows that allow light and air entering inside the building. The supports are pillars with different sections, made of still and concrete. The covers, in general, are lintels standing on the support and forming with them the skeleton, giving to the construction a light and non-weighty aspect of great constructive audacity.

5. Decorative elements The decorative elements disappear in favour of the straight and nude form. There is a worry about proportion, simplicity and asymmetry. The internal space is based of the free plan with interior walls that curve and move freely, adapting to the different functions. In the exterior the projecting, the free low level and the terrace in horizontal define the new image.

6. Building typology There is a great interest about urbanism because they aim at accommodating people to the new leaving standards and organise their groups, proposing new formulas as the garden-city o the industrial city. The most representative buildings are social houses, skyscrapers, industrial buildings, administrative constructions, theatres, concert halls and stadiums.

7. Mies van der Rohe Mies van der Rohe, was linked to the Bauhaus and is one of the best representatives of Rational architecture. His work was revolutionary from the very beginning, when he started designing an office building in Berlin (1919). After that he designed houses and in 1929 he built the German Pavilion for Barcelona’s Universal Exhibition. In this building he demonstrated the right use of modern materials, with clear volumes and the wall as a curtain instead of the traditional wall.

8. Mies van der Rohe He emigrated to the US where he built numerous skyscrapers that look to be enormous glass boxes, in which it can be seen the devotion of the architect for the purity of the forms. The use of new materials is essential for his work. The Seagram Building is one of his most representative skyscrapers.

9. Le Corbusier Le Corbusier was born in Switzerland even if a majority of his work was developed in France. He learnt the use of concrete and soon he began with the series production. He also designed cities for a concrete number of inhabitants (about three million). In 1926 he made one of his most representative works Ville Savoye, that consists of a concrete structure of Mediterranean inspiration .

10. Le Corbusier In Ville Savoye he put into practice his five points of architecture: use of “pilotis”, a kind of pillar to sustain the structure and separate it from the floor, not cutting the space; free façade; garden-terrace, thanks to the flat roofs; multiplication of windows: continuous windows with metallic sticks; free plan because now it is not the support of the wall.

11. Le Corbusier He theorised but it was not an utopian because his projects were realised One of his popular works was the Unité d´Habitation at Marseille, where he built houses for working class families. In these buildings he applied some of his architectonical points too.

12. Le Corbusier At the end of his career he modified his Rationalism and was closer to the Organicism as in the case of one of his master works: Notre Dame du Haut at Ronchamp. Other works are: UN Headquarters in New York Chandigarh in India Bagdad Stadium