The social housing project designed by PPX – Petitdidierprioux Architects is situated in a clearing within the Satory woods, on the edge of Saint-Cyr-l’École, near Versailles. The forested surroundings informed a layout inspired by a traditional farmstead, organized around a planted courtyard that functions as the social center of the project. The built volumes are interconnected, establishing a human-scale relationship between the architecture and the landscape.
A hybrid structure
The project’s setting informed a site plan inspired by a traditional farmstead organized around a planted courtyard. The courtyard functions as the central communal space, extending the forest landscape to the edge of the building. The volumes are interconnected, forming a compact composition that supports a human-scale built environment. The mixed-material structure combines a mineral base with a timber-frame curtain wall.
The project is based on a hybrid timber–concrete construction system intended to reduce embodied carbon compared to conventional residential buildings. A lasured concrete plinth at ground level provides structural stability and durability, while the upper levels are enclosed with non-load-bearing prefabricated timber-frame facades (FOB), developed off-site by GIPEN ROUX.
Prefabrication and materials
The timber-frame facade panels were prefabricated under factory-controlled conditions, integrating structural timber, thermal insulation, external timber cladding, and guardrails into a single system. Prefabrication enabled precise installation, continuity of insulation, and management of thermal bridges, while reducing construction waste and site disturbance.
Timber species such as spruce, larch, and pre-grey fir were selected for durability, controlled aging, and visual integration with the surrounding woodland. The prefabricated facade system provides consistent thermal performance across the building envelope, supporting compliance with RT 2012 requirements.
Maintenance considerations
The concrete plinth protects the building at ground level, while the timber facades and joinery are designed for controlled weathering rather than frequent replacement. Integrated facade components limit future interventions, contributing to reduced service and maintenance-related emissions over the building’s life span.
A material reuse strategy incorporated existing 40 × 40 cm concrete blocks found on site. These elements were retained during construction, cleaned, lasered to match the concrete plinth, and clad with oak slats before being repurposed as courtyard benches. This intervention applies circular economy principles at a site scale, complementing the broader timber-based construction logic.
The combination of a durable structural plinth and non-load-bearing timber facades provides flexibility for future adaptations. The hybrid system allows potential changes of use or internal reconfiguration without major structural intervention, supporting long-term resilience beyond the project’s initial residential program.
