Objet du projet
Lavoro di Master
Lieu
Altstetten Zürich
Étudiants
Signora Micaletto Enrica | Signora Ielo Federica Matilde
Encadrement
Renate Walter | Sebastian F. Lippok
Haute école/Université
USI Accademia di Architettura di Mendrisio
Semestre
Semestre primaverile 2024

The project consists of a requalification of the Hero building, located in Zürich Altstetten, through a renovation of the façade and the creation of an adequate public space for the users of the building. The existing building presents many issues, especially from a climatic point of view: the materials of the façade and the asphalt of the parking lot in front of the building increase the heat wave in this area. Although the building currently hosts different functions and is very busy throughout the day, it lacks an attractive public space. Therefore, the project focuses on the idea of a second skin that has a double effect: a climate façade, which improves the energetic performances of the building, and a façade as a generator of public space. The project raises from the research on the possibility of façades to become a unifying space, instead of a separating one. The Hero building today stands as a monumental block that does not look approachable. The double skin project runs all around it as an over-structure, articulating the building into smaller portions and making it more approachable for the urban scale. Since the owners of the buildings are different, the new façade typologies follow the division by ownerships (hence the title “6x1”), contributing to the creation of a single unifying public space. The different typologies also respond to specific climatic needs, depending on the exposition: the result is the definition of different town houses that always dialogue in the elevations, making this superblock more approachable. Moreover, the expansion of the façade also allows for an active appropriation of the space: the users can regulate this double skin to their liking and their needs, making the façades dynamic and never the same throughout the day.

The overall atmosphere of the project is completed by the landscape intervention: softer lines design a natural walk all around the building. The asphalt of the existing parking lot is removed, and the paving of this new promenade consists of reuse glass from the previous façade, mixed with bark, making the ground much more breathable; this new park takes on a playful and attractive character for the public sphere. Here, 34 species of trees and shrubs are planted in pots; the seasonality of the species becomes a motif of the public space, through different colors and smells that change during the year. The flowerbeds offer a variety of possibilities to the user: from walking to sitting, one can experience this public space in a very dynamic way. The pots for the greenery are defined by sheets of oxidized steel (with a corten effect), filled with soil, clay and bark. The pots have different heights according to the type of shrub and plant that is hosts (ranging from 50cm to 1m height).

Focusing on adding, rather than demolishing, the project allows for a richer, more dynamic and more urban friendly use of the building and of the public space.

structural description

The project consists of a steel structure, which acts as a cover and thermal protection to Hero building. The structure is slender and at the same time stable, since it is anchored to the existing reinforced concrete structure (as shown in the constructive detail). The structure defines a new rhythm of the façade, as an exoskeleton that runs all around the existing building, with a total of 141 anchorages on the ground and 160 in façade. The structure varies in the five façades: it is mostly steel, and in some cases, it integrates wood, glass and organic material. The vertical steel structure is a reuse of other structures: this is why the metal pillars and beams have different sections (rectangular, HEA, square, depending on the availability of the pieces). The structure along the entire perimeter is light, flexible and easy to maintain, assembly and eventually disassembly, without disturbing excessively the users of the building.

The pillars and beams of the steel structure are connected to each other by bolted stiffening plates; the load flows vertically through the pillars to the ground. The bracing is guaranteed by the anchoring of the new structure to the existing primary structure, making the new façade very stable.

The presence of steel is clear in the project, characterizing the façade and becoming the main trait of this renovation. The peculiarity is the use of this material in different variations, colors and treatments.

Typologies of facades

Greenhouse: This typology is in the north façade, in front of the highway: the glass shields the noise and allows natural light to enter; these greenhouses also become an extension of the floor, creating an extra space where workers can take a break. The structure consists of a steel skeleton of pillars and beams with HEA section-280x260mm.

Brise soleil: This typology is present in west the corner of the building (so it is implemented on three sides of the building - west, north and south – with different densities). It presents on the ground floor a less dense rhythm, allowing transparency and permeability with to the public outdoor area. The module consists of a wooden pillar with rectangular section -500x100mm-. The slats are screwed together and embedded in a U-shaped metal plate, screwed to the ground, which serves as a base.

Horizontal sunburst: This typology also shields noise coming from the highway to the north and allows the facade to be hit by sunlight. The system presents wooden pillars with a square section -140x140mmsupported by metal anchorage to the ground and in the facade.

Terraces: This typology corresponds to the program behind (which is various on different floors) answering the need for flexibility. It is a metal structure defined by HEA-section pillars -280x260mm and horizontal beams: the system is anchored to the facade preventing sagging and oscillations. The pillars are also bolted to a plate anchored to reinforced concrete foundations. The ground floor, once again, defines a portico, as a space in between inside and outside. Self-managing stainless steel shutters can be used by the students or the workers, allowing the appropriation of this new private outdoor space.

Green façade: Here, on the east corner of the building, different species of climbing plants clean the air from CO2 and screen the light and the noise with a different intensity, depending on the density of the structure. Structurally it is a system of wooden pillars with rectangular section -400x100mm- stabilized by horizontal currents. On the ground floor, the structure becomes a sloping passage due to the 45° inclination of the pillars. The ground anchorage is made of metal and stabilized by the presence of metal pots.