A complex and sustainable transformation in steady progress

Infrastructure upgrading, delicate interventions in molasse rock and the integration of sustainable materials: the ESSanté project illustrates a construction site where engineering, coordination and reuse advance hand in hand.

The transformation and extension works of the ESSanté school in Lausanne are progressing. The project aims to modernize the existing infrastructure to improve accessibility, internal circulation and teaching conditions, while integrating a construction approach focused on material reuse and sustainability. It includes opening the façade of the Couvaloup building to integrate a reinforced-concrete extension housing a new staircase core and an elevator, as well as refurbishing the existing building. A terrace made of reused paving slabs will complete the ensemble, while a timber walkway will connect Couvaloup to the historic Château building, improving circulation between the two volumes.

The first phase consisted of local excavation in the molasse cliff located behind the building. This delicate operation required the installation of passive ground anchors to stabilize the rock face before continuing the works.

Masonry works then began. The façade is now almost entirely demolished, and part of the building is temporarily supported by shoring to allow structural interventions. In parallel, the reinforced-concrete extension is taking shape: the first ground-floor walls have been cast and stripped, and the heads of the existing beams are being prepared for connection with the new reinforced-concrete beam that will support the future extension slab.

The future timber walkway, a key element of the project, requires precise coordination between contractors. It will bear partly on the Château façade—requiring significant core drilling—and partly on the new reinforced-concrete structure. This anticipation is essential to ensure a controlled and safe installation.

The INGPHI teams are particularly involved in managing the complex interfaces between the existing structure, the concrete extension and the future timber walkway, ensuring coherent and safe progress on site.

The ESSanté construction site exemplifies the combination of complex technical interventions, demanding geotechnical constraints and a construction approach oriented toward reuse and sustainable materials.

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Summary: project status

Completed works

• Excavation in the molasse cliff
• Stabilization of the rock face using passive ground anchors

 

Ongoing

• Demolition of the north façade for the staircase and elevator core
• Start of the main concrete works (ground-floor walls cast and stripped)
• Preparation of existing beams

 

Next steps

• Continuation of structural works: ground-floor stairs, ground-floor slab, ground-floor columns and first-floor walls
• Construction of the reinforced-concrete support against the Château façade for the reused-slab terrace, including coordination with existing scaffolding
• Preparation of supports for the future timber walkway
• Inter-company coordination for walkway installation (Château–Couvaloup link)