Adolf Loos’ Villa Müller, which he built in Prague in 1930, is perhaps one of the Viennese architect’s projects that stands out most clearly as his professional testament. Releasing architecture from the constraints of ornament and the superfluous, rediscovering its original role as a shelter for the activities of human beings, and understanding that three-dimensional space should be organised as a function of human activities, are the three great insights that prompted the design of residences such as this. According to the needs of clients, these homes were to become a tangible representation of their residents’ identity. Volume, space, light and colour all contributed to revealing the intricate and linear compositional approach of this architect who, despite his strong and complex language, helped to define the compositional lines of 20th-century architecture.

Adolf Loos was a controversial character in the history of architecture. He was not always well regarded, nor adequately recognised. There is, however, widespread agreement on acknowledging his fundamental contribution to the development of architectural compositional theory.

One of the buildings that best represent the essence of his professional experience is Villa Müller, built on a hill in Prague in 1930. The Villa presents the three major themes that marked the Viennese architect’s professional career: the lack of any ornament in spatial organisation and representation; the demonstration that an architectural environment is not an artistic expression but a response to the concrete needs of living; the application of the Raumplan distribution rules.
According to Loos, the objective of human evolution was to identify beauty according to its functional form, without the trappings of superfluous, added ornament. In many of his works Loos introduced architectural solutions that were difficult to recognise as “beautiful”, but they were unquestionably effective and practical. It is hard to appreciate the facades of the Villa Müller’s if one analyses them on the basis of their compositional “beauty”. The facades were instead to be viewed differently and considered in terms of the interior spatial organisation they provided and the efficiency of their direct interior light, which was determined by the position of each of the windows.
The organisation of the interior spaces of the house, their spatial sequence and size are the result of Loos’ analyses: they aimed solely at providing suitable solutions for the use of these spaces as environments in which to live well and comfortably.

Loos provided a reinterpretation of the dwelling concept by returning to the original purpose of architecture: to provide a shelter that was suited to human beings, a space that would reflect the identity of its occupants and in which they would always feel at ease. According to the Viennese architect, this meant that a residence could never conform to a style or trend since every dwelling had to reflect the needs of the people who would live in it and no person is like any other.
Loos’ approach to architectural composition focused entirely on proposing solutions that primarily took into account the needs formulated by each of his clients. This ensured the most appropriate use of individual rooms on the basis of the owner’s typical lifestyle. As a consequence, a temporal and functional rationale was applied to the succession of rooms and their relationship with one another. In the Villa Müller, the dining room was easily accessible from the living room and sitting rooms. Similarly, the kitchen areas were directly connected to the dining room.
This rationale partly revealed what Loos associated with the Raumplan design process. According to this theory, if interior spaces were no longer restricted to a single floor, they could be situated on different levels. Depending on their purpose and importance, rooms could vary in height as well as size, and one could make the most of a building unit by combining them into a single harmonic solution.

Were one to place the same number of rooms on superimposed levels, the liveable surface area could only be designed using a larger surface and additional circulation areas were required in addition to a different level of maintenance and less overall practical comfort than with Loos’ approach. Consequently, to reflect the idea of organising the rooms efficiently, their exterior openings, and therefore the façade, were not to follow a compositional rationale based on aesthetic canons, but could be freely expressed and positioned as needed. The exterior would thus become a veritable envelope of the interior.
The Raumplan discipline is perhaps the element that best characterised Loos’ experience, and above all, it became a highly influential architectural solution because it combined environments both horizontally and vertically. It therefore created greater value than the free plan theory that only connected spaces horizontally. Plans and elevations were no longer sufficient to design spaces using the Raumplan technique: sections and perspectives become indispensable because projects were no longer two-dimensional, but genuinely three-dimensional.

Villa Müller’s “concentric boxes” were positioned adjacent to each other at different heights, and a twisting path winded its way through the interstices with short flights of stairs and continuous changes of direction to lead visitors from one room to another. The stairs were the key to discovering the interior of the house. The path and the rooms were always in contact with one another but never physically overlapped. However, since they opened onto one another, Loos’ path allowed those who used it to observe what was happening in the rest areas; the occupants of the house, in turn, observed them. It was as if two distinct characters, one moving and the other resting inhabited Villa Müller. Loos used dimensions and materials to highlight the double nature of the spaces: the communication pathways were narrow and stone-lined, whereas the living areas were well proportioned with a prevalence of wood panelling and brightly coloured fabrics.

The path taken by the “moving” observer ended at the “heart” of the house: Mrs Milada Müller’s boudoir, a space that was literally “embedded” between the public living room, the dining room and the second floor private bedroom quarters. The owner’s personal living room was, therefore, positioned to protect the most private areas, while at the same time it opened onto the living room, just like a theatre box. The small window above the sofa niche allowed the mistress of the house to look down and “supervise” what happened below. Everything in the room evoked a feminine presence: the unusual, light-coloured lemonwood panelling, the sofa’s floral upholstery, and the highly intimate dimension of the niche itself.
But the interplay of glances was two-sided: the person controlling was actually also controlled, and when Mrs Milada sat on the sofa in her Damenzimmer and turned her back to the window facing the living room, she was not so much controlling as controlled. The spatial system designed by Adolf Loos was ambiguous, the observer and the observed exchanged roles. Here, as in some of his other projects, the designer organised the interiors to suit the daily habits and activities of their owners.

In Villa Müller, we find once again a sharp separation between internal and external space. While the almost cubic volume of the villa revealed nothing of its domestic intimacy, a cross-section of the interior reveals the multiple levels, as well as the marked compenetration of spaces. The Raumplan’s interlocking volumes were both a play on volumes entirely enclosed within a single unit that looked elementary on the outside, and the sequential design of pathways and outlooks: it was almost as if the characters inside the rooms were being presented on a theatre stage. This compenetration of spaces was instrumental to the characters’ actions, whether in motion or at rest.

Adolf Loos was a true supporter of modern architectural ideas. In keeping with his philosophy of distinguishing between public and private spaces, he focused his attention on the interaction between a building’s form and its function.
These ideas formed a conceptual model with which to explore the relationship between the overall space of a house and its internal circulation system. This construction theory did not imply a division into individual floors, but rather a division into a variety of spaces and single environments to be interconnected at different levels.

“My architecture is not conceived in plans, but in spaces. I do not design floor plans, facades, sections. I design spaces. For me, there is no ground floor, first floor, […]. For me, there are only contiguous, continual spaces, rooms, anterooms, corridors, terraces, etc. The levels merge, and the spaces relate to each other. Each room requires a different height: the dining room is naturally higher than the kitchen or the pantry, a toilet does not need the same height as a living room; therefore ceilings are at different levels. For me, the only logical consequence is to link these spaces together so that ascending and descending are not only imperceptible but also practical.”
A recess in the volume of the facade marks the entrance to Villa Müller; a canopy emphasises it plastically and produces a shadow over the facade and its extensive travertine cladding.
An explosion of colours in the entrance underscores the transition from an entirely white outdoor setting to the interior. To a certain extent, the colours foretell possible scenarios that will be discovered in subsequent interior spaces. From this area, one enters a hall that leads directly into the double-height living room, the room from which the staircase departs and connects the other parts of the house, all the way up to the bedrooms located on the highest level.

The whole system of staircases and hallways that start from this area is a sequence of connected environments: the sitting room communicates visually, through two openings, with the living room. One can descend a further flight of ten steps from the writing room directly to the living room. If you walk down four steps from the living room, you are in the library, the only area that is completely isolated from all the others; if you climb the same number of steps, you are in the summer tearoom that overlooks the terrace.

Carefully chosen colour schemes differentiate the rooms one from another. Adolf Loos was well aware that the spaces, shapes and colours of the living areas affected the character and moods of their occupants. In this instance he chose pure complementary colours, diversifying them according to the intended use of each room. Warm shades were selected for the materials of the fixed and movable furnishings with the intention of creating welcoming and relaxing spaces.