Primary school
A preserved space near a residential neighborhood, its contours shaped over the years by the passage of water that gradually carved out these sunken lanes. To access the site, one crosses the wooded edge and discovers the meadow: a protected landscape with trees as its horizon. All the classrooms benefit from an unobstructed view of the generous playgrounds, with this wooded edge as a backdrop. It is this clearing, this inner landscape, conducive to the establishment of a school, that we wanted to capture: a world apart, both a protected space and a place of learning, experimentation, and discovery.
The project seeks to reconcile a strong bioclimatic design while taking advantage of the site's inherent poetry. The new single-story school complex forms a built island where each volume is revealed gradually, never fully obscuring the project as a whole. The interplay of volumes, characterized by a succession of large, single-pitched roofs, allows each program to benefit from maximum volume, ensuring optimal comfort (light, natural ventilation, overheating control, etc.). The sunken pathways of the forecourt guide schoolchildren towards the recesses marking the entrance. These recesses extend into the school, creating a street open to the outside.
The central patios, veritable green lungs, become meeting places and offer the opportunity to develop new, outward-looking teaching methods. The single-story school fosters connections between indoors and outdoors and provides all classrooms, workshops, and the cafeteria with a panoramic view of the tree-lined courtyard. The new school complex embodies the image of "the school of tomorrow," generously open to the outside world.
The construction of a school complex using timber framing, straw bale construction, and load-bearing cob requires close collaboration, mutual support, and trust among all project stakeholders. Even before our project management team joined the project, the client was selected as a winner of a Call for Expressions of Interest for "building with raw earth and bio-based materials," organized by FB2 (Breton Bio-based Federation). The project owner (MOA) benefited from support from a bio-based and geo-sourced materials expert, commissioned by FB2, during the consultation with the project manager (MOE) and the subsequent studies. Once our team was selected in September 2022, the ambitious project schedule (9 months of studies, 18 months of construction) required close collaboration between the project owner, project management assistance (AMO), inspection agency, and project manager (MOE) to overcome all the regulatory hurdles encountered in the application of raw earth materials. The project aims to utilize the site's soil (unstabilized and therefore remaining in its original state) using five techniques: load-bearing cob, wattle and daub partitions, lightweight earth and straw, earth and hemp insulation, and interior and exterior earth plaster. Regulatory constraints, particularly in terms of fire safety and seismic justification, required extensive work throughout the studies to define a framework which, like any experimental framework, might not succeed because the objective remained to deliver the school in August 2025 without the possibility of resorting to an ATEX or site notice.
During construction, we selected a Temporary Joint Venture for the raw earth package, with five companies joining forces to meet the project's technical challenges: 470 tons of earth from the site were used in five different applications, all within significant site constraints (seasonality, scheduling, and coordination with other trades). Once again, driven by a shared objective, our project management team, working with the client and the contractors, demonstrated tenacity and resilience to successfully complete this challenge. Such a project could not have been achieved without this collaborative effort between the project management team, the client, and the contractors.
Our design revolves around the concepts of frugality, simplicity, efficiency, and sustainability, aiming to limit resource consumption. The project relies on passive design features (orientation, solar gain, high-performance thermal envelope, natural ventilation, thermal lag, natural lighting) and on bio-sourced, geo-sourced, and locally sourced materials. The project gives pride of place to raw earth and wood.
The Clearing School is largely constructed with a timber frame (portals and timber-frame construction) with straw bale insulation (22cm bales + additional biofiber) and raw earth: four large volumes at the entrance are entirely made of load-bearing cob, and all the partitions between classrooms and circulation areas are made of timber framing with cob infill.
At the site entrance, the walls are constructed of structural cob (unstabilized raw earth from the site) using the "paton" technique. Insulation consists of a mixture of earth and hemp sprayed onto the cob wall (on the interior side), and earth plasters are applied as a finish on both the exterior and interior. This nearly 65cm thick wall provides remarkable humidity control and thermal and acoustic comfort appreciated by all users.
The cob partitions are made of timber-framed walls filled with raw earth mixed with straw in the form of "torches." An earth plaster on each side, leaving the timber frame visible, completes the wall. This 18cm thick wall, with its very high thermal mass, is used for passive cooling. The classrooms are designed with windows on both sides (opening in the upper part of the cob partition + 100% glazed walls facing the playground), which promotes air circulation and therefore natural ventilation day and night. The raw earth wall, with its high thermal inertia, releases the coolness stored overnight during the day (free cooling), resulting in a temperature reduction of 4 to 5°C during periods of summer overheating. Earth and wood complement each other in a project that carefully considers the optimal use of each material's characteristics.
