42UP extends École 42 in Paris’s 17th arrondissement through a vertical addition that more than doubles its usable area without expanding its footprint. Designed by AR Studio d’Architectures, the project transforms an existing 3,600 m² structure into a 9,025 m², continuously operating campus that accommodates 1,400 workstations in a dense urban context.
42UP Vertical Campus Technical Information
- Architects: AR Studio d’Architectures
- Location: Paris, France
- Gross Area: 9,025 m2 | 97,146 Sq. Ft.
- Project Years: 2022 – 2025
- Photographs: © 11h45
We chose to build upon what was already there, using structure and section to multiply space rather than consume more ground.
– AR Studio d’Architectures
Vertical Expansion as Architectural Frugality
Rather than replacing the existing school building, AR Studio d’Architectures preserved its structural framework and extended it upward. The intervention transforms a constrained urban parcel by increasing the floor area from 3,600 m² to 9,025 m² through the addition of four base volumes and a five-level steel superstructure rising 18 meters above the original roofline. This densification strategy leverages the site’s latent capacity while minimizing demolition and limiting disruption to the ground plane.
The sectional reorganization is central to the project’s logic. By consolidating vertical loads into strategic cores, the architects free the footprint for continuous learning spaces and shared amenities. The expansion serves as a precise structural overlay, acknowledging the limitations of the existing building while extending its capacity. Vertical growth is both a pragmatic and a spatial response to urban land scarcity.
Structural Expression and Spatial Continuity
The most striking gesture is a suspended steel volume that bridges above the preserved structure. Supported by vertical circulation cores and a 42-meter transfer beam, this elevated body creates a column-free third floor. The absence of internal supports produces a large, uninterrupted workspace that opens toward the city through carefully framed views, reinforcing the sense of elevation both physically and perceptually.
Circulation cores perform multiple roles. Structurally, they anchor the superstructure and transfer loads downward. Spatially, they concentrate stairs, elevators, and services, releasing the surrounding floor plates for flexible occupation. This consolidation of infrastructure allows the interior to function as a series of open fields rather than a sequence of enclosed rooms. The new white volumes contrast with the retained black façade, establishing a clear distinction between past and present while maintaining volumetric alignment.
Envelope as Environmental and Urban Interface
A white perforated metal skin wraps the entire composition, unifying existing and new elements within a single architectural language. The façade is structured on a 1.17-by-1.17-meter grid, which transitions into triangular modules across the upper levels. This transformation introduces depth and subtle variation, producing a shifting pattern of light and shadow that changes throughout the day.
The micro-perforated envelope performs as an environmental buffer. Housing 1,400 heat-generating computers in a building that operates continuously demands careful solar control. The screen reduces direct heat gain while maintaining visual permeability and daylight access. Its porosity adjusts the perception of scale from the street, mediating between the surrounding urban fabric and the elevated superstructure. The envelope, therefore, functions as both a climate regulator and an urban interface.
Interior Flexibility and the Reimagining of Educational Space
The interior rejects the conventional classroom model in favor of expansive, open-plan floors. Designed to support peer-to-peer learning and continuous use, the layouts maximize density while maintaining spatial legibility. Workstations are organized in large communal halls, with circulation directed to the perimeter. Alcoves carved into stair cores and edges provide quiet areas, offering a gradient from collective activity to focused concentration.
Material choices respond to the acoustic demands of a 24-hour digital workspace. Wood-wool panels and textile finishes absorb sound, mitigating the intensity of constant occupation. Each level is defined by a distinct chromatic identity, aiding orientation within the stacked program. Beyond work areas, the campus includes an amphitheater, library, gym, recording studios, dining spaces, and rooftop terraces designed as elevated gardens. These terraces extend the learning environment outdoors, linking the vertical campus to the adjacent student housing and situating the school within a broader urban ecosystem.
About AR Studio d’Architectures
AR Studio d’Architectures is a Paris-based architecture practice founded in 2015. The studio approaches architecture as a process of transformation and densification within constrained urban contexts, emphasizing structural clarity, material economy, and the adaptive reuse of existing buildings. Through vertical extension and spatial reconfiguration, the practice seeks to expand capacity while minimizing demolition, articulating a contemporary architectural language rooted in frugality and urban integration.
Credits and Additional Notes
- Structural engineers: I+A (concrete structure)
- MEP consultants: CD Conseil
- Landscape designers: Atelier MOABI
- Client: 42, the digital professions school founded by Xavier Niel and NJJ Immobilier
- Structure and Envelope: Léon Grosse Fondations
- Steel Structure: Baudin Chateauneuf
- Façades: STIM TECHNIBAT
- Electrical: CESA
- HVAC: SOFTAIR
- Interiors: CESAM
- Kitchen: MRG
- Façades: VP & Green
- Acoustics: Neo dB
- Construction Management: EGIS
- Technical Control: BTP Consultants
- Fire Safety: CSD & Associés
- Street Art Curation: Nicolas Laugero Lasserre
