Apartment Building Fragment - process

Vision
Originally an industrial district, Karlín has long been undergoing a transformation that defines its role in the current life of the broader center of Prague. In terms of demands for contemporary living, Karlín has become a sought-after quarter for housing, job opportunities, and leisure time.

For the residential building Fragment, we are creating a concept of visually strong, unmistakable architecture that responds to the context of the location with regard to both its past and future.
Alongside formal and functional considerations, it is primarily the organic connection to the public space that the building Fragment expands, makes more accessible, and functionally and visually enriches. An integral part of this program is a monumental sculptural work by artist David Černý, which has been part of the authorship collaboration on the concept of the entire object from the outset.

Context
The gradual revitalization of the area has allowed for the preservation of the original scale of old Karlín. Modern construction of solitary buildings at the Invalidovna housing estate serves as a counterbalance to its classic block structure. The Fragment building, situated at the boundary of both zones, responds to contrasts in architectural history and strives for a harmonious completion of the site.

The chosen architectural form of two arms converging into one block corresponds to the trapezoidal shape of the plot and the character of the surrounding buildings. Fragment embodies a transition, or rather an intersection of two worlds. The two masses of the building on one side evoke a block of buildings, while the mass on the other side represents solitary construction. The process of the disintegration of block development is also indicated by the pixelization of the façade mass.

A strong determining factor is also the contact with the historical Invalidovna building, to which the house is oriented. "With full respect for the qualities of Invalidovna and the energy inherent to this place, we position Fragment in a contrasting role—acting as a mark of the present time. We bring an equal dialogue of the existing and the new to the transformation of Karlín, which we understand as a logical condition for quality development."

Fragmentary structure of a compact whole
In plan, the blocks form a compact whole settled on a uniform transparent plinth at the ground level. As it rises, the individual fragments dynamically move in response to their external and internal environments. The playful, relaxed shape of the building is contextual rather than formal.

Careful compositional gradation of mass communicates with the different scales of surrounding structures and other environmental factors. On one side, it adapts to the traffic intensity of Rohanského Embankment, while on the other side, it takes advantage of all the pleasant qualities of the environment, such as the immediate proximity to the greenery of the adjacent Kaizl Gardens or views of the significant landmarks of the broader surroundings, such as Vítkov.

The retreating masses of the building optimally set the apartments and the communal atrium to allow the flow of daylight—the atrium opens up, the space expands, remaining unconfined and playful.
Boxes that alternately protrude from the upper and lower parts of the block create a play of light and shadow, enhancing the perception of the façade's variability—of forms—over time.
From the position of a passerby, the individual "boxes" fragment the whole block into a pleasant human scale.

Public space
Openness and transparency are essential for the concept of the building. In terms of continuity, permeability, and cultivation of public space, the position relative to the Invalidovna and the park is important. A natural trajectory of movement flows between the two objects. At its mouth, Fragment spreads, and the mass of the building is carved out. The visitor enters a spacious covered area with sculptures, greenery, and a water feature, which provides a background and a pleasant atmosphere for moments of relaxation for residents and the public. Along this axis, the building is passable. The ground floor of the building also serves the public with services and small shops.
The atrium is then a calm space, partially paved and partially filled with greenery, including the roof and the first floor.

Technical solution
The Fragment residential building offers individual rental housing in a combination of smaller, medium, and larger apartments. Boxes measuring 3.8 × 3.1 m contain one room, and by connecting additional modules, larger living units are created. Thanks to a single investor, the building is designed as a single functional whole with logical connectivity among all operations and maintenance.

An important attribute of this dynamic building is, of course, its construction. Initially, architects considered a comprehensive prefabricated solution from conception, optimization to transportation and assembly on site, including prefabricated bathrooms. The investor opted for a reinforced concrete construction.
"Throughout the entire process, we highly value that from the initial sketches to the finale, there was no change in the form of the building, not only for compositional reasons but primarily for technical reasons," says David Wittassek, the project's chief architect. Minor corrections only pertained to enhancing the construction's efficiency.

For the façade, several technical variants were considered. It was crucial to maintain the original shape and proportional solution of the boxes, including the loggias. Details must fit perfectly, be aesthetically pleasing, and functional. Today, construction production is therefore moving into workshops and becoming machine engineering, which is also the case for the Fragment building. During assembly, for primarily technical reasons, a separate assembly of the opening infills was undertaken, followed by the assembly of the ventilated façade.

For the façade material, we chose aluminum composite panels. The effects of weather alongside the complexity of the building's façade enhance the impression of variability over time, embodying a living building. The city and the building are a living, unfinished process.

The building incorporates technologies standard for the 21st century today, such as green roofs, solar panels, heat pumps, rainwater management, and utilizing its own underground water resources.