Sumit Singhal loves modern architecture. He comes from a family of builders who have built more than 20 projects in the last ten years near Delhi in India. He has recently started writing about the architectural projects that catch his imagination.
Restructuring and extension of the Proudhon secondary school in Besançon, France by Tectoniques architects
July 8th, 2015 by Sumit Singhal
Article source: Tectoniques architects
Proudhon secondary school was built in 1971. It is located in the Palente district, to the north of Besançon. It is surrounded by the Pergaud sixth form secondary school and the Orchamps gymnasium. The original architecture is typical of the mass urbanisation of the 1960s and the policy of standardisation, two phenomena which forged the “ordinary” heritage of the 20th century.
The Tectoniques architectural firm in collaboration with Architectures Adelfo Scaranello won the competition to restructure and extend the facility. The school had to remain open throughout the duration of the building works. The project was therefore broken down into phases in order to continue to accommodate pupils and staff throughout the construction and renovation work. After three years of work, a unifying, holistic project was delivered. The only teaching block of classrooms that was preserved also happens to be the largest and forms the focal point for the whole programme.
The new secondary school benefits from a more compact programme which offers gains in terms of quality of use and heating conservation. It develops around a large gallery which spans the whole facility and organises the distribution. The south-facing urban facade overlooks the Palente district, whilst to the north there is a more contemplative opening across the expansive landscape of the Chailluz forest.
The architectural style for the Proudhon secondary school is deliberately sober and unifying. The intention was to move away from the principle of compiling different objects which so often underpins this type of project. Even the SEGPA workshops and canteen are absorbed into the overall design. The only exception is the contrast drawn between the new building and the renovated building. The first forms a black, slightly metallic body, whilst the second is a white, matte block.
Giving the 1970s a new lease of life
What strategy should we adopt when approaching these highly standardised and architecturally dated buildings? How should we go about ensuring they comply with contemporary standards in terms of comfort and the environment? These were the main questions the project had to answer.
The Tectoniques firm has often had to tackle these challenges, notably in recent projects to renovate holiday accommodation in the La Plagne and Grande Motte resorts. As for AAS, they have worked on numerous secondary school projects. The school was originally composed of six separate buildings, some of which were connected via external walkways. Only two of these buildings are still in place: the main classroom building and the staff residences which are set back from the main buildings.
The main teaching building is composed of pre-fabricated concrete components fixed onto a 1.75 m grid framework over four floors. The facade is solely and systematically composed of 1.75 x 1.75 m boxes which emphasises the industrial feel to the construction. Only the structural works were preserved.
The aim of the renovation work was to make the building smoother and more neutral, by absorbing the different details of the faceted moulding, and to ensure compliance with French heating conservation standards. The external insulation reinforces the abstract effect created, by removing the design and layout of the prefabricated concrete panels. The decision was made to make the building white.
This choice of colour contrasts with the contemporary extension whilst remaining neutral and peaceful. Inside the building, patches of colour are used to effect a change of atmosphere and to define the different levels. Unfortunately, for acoustic reasons, the architects could not leave the soffits of the box flooring visible as is typical of this type of construction.
The constraints of working in an occupied site means the phasing of the project was particularly complex. The work had to be carried out with the greatest precision as the old buildings were demolished in extremely close proximity to the newly-built structures which led to some very tense situations. A total of 76 bungalows had to be set up to compensate for the shortage of space.
The extension continues on from the renovated building, along the same lines, thus creating a coherent, balanced volume. The mass and height of the teaching block, sandwiched in the middle, dominate the composition. It is a point of anchorage, a fulcrum at the centre of the project.
The contrasts in texture between the dark and shiny finish of the new building, and the white and matte finish of the old building, clearly reflect the history and nature of the structures. The original prefabricated concrete building has been externally insulated using polystyrene foam and fitted with PVC window frames and shutters, finished with a synthetic coating.
The new building is made of wood with a high performance insulated shell, aluminium window frames and mobile sunshades, with a wood fibre and thermo-setting resin finish. Despite the opposing tectonics of the two blocks, their co-existence is balanced and peaceful.
An extensive programme:
The Proudhon secondary school is attended by 700 pupils in a vast programme adapted to both mainstream teaching and special learning needs in the SEGPA (offering vocational courses in construction, hygiene and service and cookery) as well as inclusive classrooms for children with disabilities.
The organisation is clear, legible and rational. Four blocks branch off the main gallery which forms the backbone of the project and links the different buildings. It is designed as an internal street that is both varied and clearly identifiable.
– A: The SEGPA are located in the north-west section with special access for deliveries of adapted equipment
The distribution and circulation spaces determine the geography of the new school. They are large and wide, opening out onto the landscape. The interplay between galleries allows a smooth transition between the different floors. Rather than simply offering a functional transition, these areas are genuine spaces that are both dense and complex, where the structure of the project makes it presence felt. In this sense there is an educational aim, these are spaces which display how they are made and what they are made of, for all to see.
The playground, to the south, is a mineral structure with an urban status, interacting with the public alleyway created as part of the project along the southern perimeter of the school. The covered part of the playground is an internal space that spans the building, placed at the centre of the facility. It forms the lobby of the new school. The main gallery runs along the facade. It is mostly glazed and has views of the Chailluz forest. The garden, to the north, is protected by the building which wraps around it. The open views and landscaped areas contrast with the southern playground and can be used for different purposes. A series of patios mark out the physical connection between the north garden and the lower section of the plot. The system is both topographical and playful
Concrete core-walls provide overall stability and act as firewalls for the at-risk areas. The project expands out from these solid anchors with a wooden structure built using a beam-column system. The beams run up to 1.15 metres to manage the long spans and overhangs.
Seismic design regulations were modified during the study and design phase of the project. The structure was therefore adapted with significant changes made in terms of sizing and jointing.
All the new buildings are built using a 2.10 metre framework and multiples thereof. This framework is used for all the structures. It is visible on both the interior and exterior of the facade, on the ceilings, and vertically on the internal structures which are also left on display. This system creates a repetitive, regular pattern that is characteristic of wood structures composed of a gigantic set of prefabricated parts. The layout of the facades and exterior cladding reflect the composite nature of this construction material.
To the south-east, a deep overhang works with the vertical sunshades to provide additional protection and regulate the amount of sunlight entering the building. To the north-west the overhang is less pronounced, but the sunshades are larger to protect the space from the sunlight at the end of the day. The sun protection systems are composed of rock fibre panels (Rockpanel). The other parts of the facade are clad with panels made of wood-based fibres and thermo-setting resins (Trespa).
Prototypes were produced before work began to test the different components used for the framework, sealing, exterior woodwork and frames.
In terms of the environment, the project complies with the most recent heating conservation regulations in France which were brought in in 2012. The passive components of the project make the most significant contribution to improving heating efficiency: the extensive use of wood, the external insulation (wooden framework with rock fibre (14cm) and wood-fibre finish (5cm)) and the air tightness (testing carried out on completion of the work).
Main products and systems
Facades of the renovated teaching block: white coating, PVC frames. Facades of the new buildings: TRESPA cladding panels in malachite green, trimming and sunshades in Rockpanel basalt composite panels, aluminium work. All the buildings are equipped with sun protection with mobile, inclinable blades.
Contact Tectoniques architects