The BELЯ project, commissioned by Baltisse and carried out in collaboration with Fabeck Architectes, CES, Wust Lux, Seco, D3 Coordination, SPIE, Demalux, D2S International, Vereal and DF Associés embodies this philosophy: the sustainable conversion of an office building into a residential building. This initiative demonstrates how architectural transformation can go hand in hand with environmental responsibility and economic viability.
Following an initial feasibility study led by Fabeck Architectes and Baltisse, the decision was made to preserve and adapt the existing building, located in the Belair district of Luxembourg City, and to commission Schroeder & Associés to optimize adaptation work on the existing structure.
Reinventing without demolishing: this is the guiding principle of Schroeder & Associés committed to sustainable, smart, and respectful construction. Their approach focuses on transforming existing buildings to better meet ecological challenges and to promote long-term, harmonious integration into the urban landscape.
Antoine Pesch, partner and department head, and Éric Jans, senior engineer in the building and civil engineering department, were both strong advocates for conserving and reusing the existing structure rather than resorting to extensive demolition – a process that would have generated substantial waste and a significant carbon footprint. A crucial element in this decision was access to the original construction plans from the 1980s, preserved in the engineering office’s archives. These historical documents proved to be invaluable for the design and engineering teams, offering precise information on the geometry, dimensions, and resistance of the building’s load-bearing elements. This enabled a reliable assessment of structural integrity and avoided many invasive, costly, and time-consuming surveys. These savings directly contributed to more effective cost control and efficient planning of technical interventions.
BELЯ project (Photo: Fabeck Architectes)
«Having access to these plans allowed us to anticipate constraints and drastically reduce unexpected technical issues, which often lead to delays and additional costs on-site,» explains Éric Jans. Moreover, this approach had a positive impact on the daily lives of tenants still occupying the building before the conversion began. Fewer probes meant fewer nuisances – less vibration, noise, and dust. “Not only did this simplify the planning of the works, but it also preserved the living conditions of the occupants during the design phase,” he adds.
The choice to retain the original structure reduced resource consumption and extended the building’s life cycle. The project was based on a detailed analysis of what could be preserved. “We reversed the traditional logic,” Éric Jans points out, “by first assessing what could be saved before defining what needed to be removed.”
From an environmental perspective, the use of original plans also helped minimize unnecessary structural interventions by reducing the need for reinforcements and adjustments. This careful approach, combining technical know-how and historical documentation, underscores the added value that archival research can bring to ambitious and sustainable renovation efforts.
The project’s carbon footprint saw significant reductions. Preserving the reinforced concrete structure avoided emissions associated with the production and transport of new materials. Structural work was limited to what was strictly necessary, minimizing construction waste and the use of natural resources.
This initiative aligns perfectly with the goals of the “House Europe!” initiative, which promotes the sustainable renovation of the built environment to meet social and ecological objectives – supporting conservation to rapidly provide housing with the lowest possible environmental impact.
BELЯ project (Photo: Schroeder & Associés)
A major architectural intervention involved opening up the façades to integrate balconies made of prefabricated concrete – accelerating the timeline while reducing on-site disruption. These new private spaces not only enhance resident comfort but also improve natural interior lighting. Additionally, transforming the roof into a mansard structure allowed the creation of duplex apartments, optimizing natural lighting.
A major architectural intervention involved opening up the façades to integrate balconies made of prefabricated concrete – accelerating the timeline while reducing on-site disruption.
This project serves as a compelling demonstration that preserving and optimizing existing structures is both feasible and desirable. Antoine Pesch emphasizes the importance of thorough preliminary analysis, backed by specialized engineers and supported by archival documents when available. For Éric Jans, the success of a conversion project hinges on early and close collaboration among all stakeholders involved.