The site proposed to host the Toulouse archives in the department of Haute-Garonne is characteristic of an open suburban fabric where vegetation plays an important role. The building’s geometry is a shape suited to conservation. It reflects the strict lines of a 2-storey design whose elements were drawn from an initial “pure” shape. The building is discovered gradually behind its monolithic appearance. It is made of a double concrete envelope. The first is structural and the second is a trim which gives a standard appearance and surface for the building. The concrete cladding is integrally coloured with slightly ochre-coloured pigments, helping the structure to blend into the landscape. To reach the desired result, the monolithic building has no joints, with concrete cast in place over time in successive layers. This layered coating reflects the passing of time and symbolises the successive layers of memory. The joints are created edge to edge, without linking framework; the panel or formwork layouts are removed with no formwork holes. The facade absorbs the geometric variations through its horizontal concrete layers. Whilst the building is mainly used for storage, particular care was taken with the quality of use of the interior spaces. The architecture aimed to provide more natural light for users. The inclusion of different sized cylindrical glass windows forms scattered openings in the side walls, allowing light to stream into all corridors. These openings also offer a distant view of the landscape to the users, resulting in comfort and quality. The same technique is used in the warehouses. The sorting rooms are bathed in natural light with a succession of regular vertical bay windows. The relaxation, professional consultation, office and storage rooms have large bay windows overlooking a leafy patio.