This is the home of Roberto, the owner of Casa Flix, a 42m² flat located on the first floor of a sixth-floor building in the center of Madrid, built in 1900. The spatial configuration of this attic flat, distinct from the rest of the building, adheres to urban planning regulations that typically feature sloping roofs, large rooms with few partitions, and low ceiling heights.

Originally laid out with two rooms—a 10x4m rectangle and a 3x3m square—both featuring sloping roofs, this compact house aims to create an optimal, flexible, diverse, and bright living space. The design focuses on efficient use of the floor plan and, more importantly, the vertical section.

The house is designed to be divided into four areas interconnected both physically and visually, arranged from north to south: the bedroom/dressing room, the entrance area, the workspace/bathroom, and the kitchen/living/dining room.

The washbasin and toilet are discreetly housed within a closed volume paneled with 2.10m-high mirrors. Accessed through a secret door from the entrance, this mirrored cabin expands the perceived space and offers various perspectives depending on whether the door is partially open, fully open, or closed. Meanwhile, the shower is positioned within the room, separated from the rest of the house by a glass block wall that allows natural light to illuminate the space during the day.

The bathroom occupies the heart of the house and is designed in an atomised form, where the sink and toilet are made independent of the shower within a width of 90 centimetres.

The entrance is a tall and elongated space measuring 8.20 metres in length. It comprises an exterior part that serves as a terrace for accessing the house, and an interior part resembling a blue tunnel. Inside, there is a metal shelf and a circular window, evoking the interior of a ship.

The kitchen furniture is designed as a linear structure measuring 5.5 metres in length, 0.6 metres in width, and 2.02 metres in height. It includes a volume that stores the majority of objects, such as cleaning products, kitchen utensils, appliances, and clothes. A compact wall, laminated in HPL ultra-matte pale yellow, adds brightness and is constructed using standard market measurements to minimise costs.

To enhance the apartment's natural light and ventilation, two additional roof windows are installed—one in the bedroom and another in the living room. The entry door to the apartment is replaced with a transparent glass door, which allows light to filter through even when closed.