Inside the massive walls

A building that does not claim eternity - this is what the 'Centre d’Interprétation du Patrimoine' built inside the castle of Brie-Comte-Robert was meant to be. A light, transparent structure that could be easily removed in case of doubt. Behind its larch façade, the museum hides halls filled with daylight, where the exhibited artifacts, the reconstructed walls of the castle, and the modern wooden structure find mutual harmony.

Approximately 30 kilometers southeast of Paris, amidst the hilly landscape of Brie stands a monumental work that is listed in only a few guides and which, according to historians, is allegedly the model for many French medieval castles. Château de Brie-Comte-Robert, a construction with a square plan and round corner towers, lies just a few steps from the marketplace in the center of the small town of the same name. Like hundreds of years ago, two bridges today lead visitors to two castle gates, which are protected by four-sided towers. This opening and the resulting corridor-like character of the castle is, as far as we know, a unique feature in the region.

The castle was built at the end of the 12th century by Robert I de Dreux, the lord of Brie and brother of the French king Louis VII. By 1982, not much was left of the structure, aside from a few remnants of approximately 2.3-meter-wide limestone walls. Since then, however, the Amis du Vieux Château, an association of volunteers, has achieved several significant successes. A large portion of the castle walls, along with all eight of its towers, has been rebuilt. In addition, excavations in the inner courtyard have uncovered numerous fragments of walls from former residential buildings. Those who conducted the excavations were supported in their efforts by many private and public sponsors, who also provided funding in 2003 so the association could realize its most ambitious project to date - the construction of a combined operational and exhibition building, officially known in French as the Centre d’interprétation du patrimoine (CIP). The goal was for the building to house not only an exhibition hall but also rooms for the museum's educational activities, offices, and a large meeting room for archaeological volunteers.

The plans for the new 400 m² building, valued at 725,000 euros, were developed by local architects Semon/Rapaport and museum designer Lorenzo Piqueras. As is customary in cases where a new building is planned within a historic site, the National Heritage Authority (ACMH) also had a significant say in the building regulations. Its chief architect Jacques Moulin drafted a specification document for the project that required a wooden structure - partly to ensure that this material would clearly distinguish itself from the old walls, and partly because a wooden structure could be relatively easily removed later to make way for subsequent extensive excavations. Aesthetic considerations also played a role in Moulin's preference for wood: "The medieval monuments we care for often resemble shells, where the only remaining part is their casing. All the lighter structures have disappeared. […] Therefore, I find it desirable to reestablish this diversity of materials in renovated buildings, as it was a typical feature of Western architectural design."

And ultimately, it was also the lower weight that is a significant advantage of the wooden construction; archaeological work has not yet taken place at the site of the building in the northern corner of the castle. To protect the artifacts that are potentially still hidden here, the land cannot be burdened with any heavy constructions or heavy construction equipment. The museum was built as a purely frame structure and is based on individual flat footings that rest on the natural ground. The regulations of the heritage office required that its height should not exceed that of the newly erected walls.

The architectural office Semon/Rapaport designed the building in the shape of an L with a single-pitched roof, which seemingly rests against the castle walls to the north and east, while opening to the midday sun to the south. The construction of the roof is supported by round columns made of Douglas fir, some of which are anchored to the castle wall using tension rods. Some of the exhibition displays inside the museum are also set into the reconstructed rear wall. The wooden design allowed large sections of the floors, walls, load-bearing beams, and roof structure to be prefabricated, and the on-site construction work could be completed in just three weeks.

Access to the museum is from the ground floor through a wide wooden platform built in front of the building. The southern façade reflects the use of individual rooms - and the architects' desire for the museum, which is in sharp contrast to the 'black boxes' and 'white cubes' typically found in similar places, to allow visitors to observe how the sun moves around the building.

At eye level, the façade is predominantly closed and can be used for hanging exhibits. However, Semon/Rapaport provided the exhibition hall with three strips of windows that allow visitors to look outside. One is located directly above the floor, another below the suspended ceiling, and the third is incorporated into the roof of the museum to allow daylight to access the back third of the exhibition space. On sunny days, these windows allow daylight to penetrate through the rough limestone walls, occasionally outlining the contours of individual exhibits.

Historical artifacts, reconstructed masonry, and the light new structure continuously present themselves in a new - and constantly different - light. For the strip skylights, the architects used roof windows. "This choice allowed us to keep costs low compared to the prices of special aluminum fillings, and additionally, it is possible to ventilate the space,” explains Jean-Claude Semon. The museum almost automatically maintains a pleasant climate without temperature spikes. In the summer, the massive castle walls act as an ideal temperature buffer, protecting the building from overheating, while in the winter, a low-temperature radiant heating system has been installed in the ceiling of the hall.