- Building Type : School, college, university
- Construction Year : 2019
- Delivery year : 2021
- Address 1 - street : 44 rue Hussenet 93110 ROSNY-SOUS-BOIS, France
- Climate zone : [Cfb] Marine Mild Winter, warm summer, no dry season.
- Net Floor Area : 3 369 m2
- Construction/refurbishment cost : 11 406 536 €
- Cost/m2 : 3385.73 €/m2
Primary energy need :
(Calculation method : Other )
The increase in population generalized throughout the city, led to the design of a school with 11 classes of 3383 m² SDP. The design began in September 2018 for delivery in September 2021. This schedule imposed prefabrication, with however the ambition to develop insulated wall boxes in organic straw from the Ile-de-France region (77) coated on both sides int./ext. . Despite the time constraint, the team organized participatory wood-burnt workshops and supervised the collection and transformation of a small part of the wood from the school to the Villarceaux estate (95).
The creation of the Simone Veil school group is part of a process of serving the common good. For this, the team ensures that its actions are positive or neutral on the ecosystems. This ethical research is built around the following principles:
- Local resources : identify available unprocessed resources, as well as the origin and environmental impact of each architectural element;
- Social intensity : Citizen architecture that reintegrates the act of building by promoting professional integration companies and participatory construction sites;
- Alternative pedagogies : Architecture, support for a pedagogy advocating the collective development of the eco-citizens of tomorrow.
A market with an adapted procedure: procedures with negotiations.
Building users opinion
Children, teachers and staff quite satisfied with the building.
If you had to do it again?
If it were to be redone, the best would be not to build... Or smaller, change scale to tend downwards...
See more details about this projecthttps://www.ekopolis.fr/operation-batiment/groupe-scolaire-simone-veil
©Research and Innovation Department and ©Juan Sepulveda
Other consultancy agencySEMOFI Geotechnical study office
Environmental consultancyAPAVE SUD EUROPE Control office
CompanyMenuiserie David et Fils Carpenter
CompanyAPIJ BAT Wood and straw construction, plaster on straw
ManufacturerLenoir Bois Sawmill
- 42,00 kWhep/m2.an
- 50,00 kWhep/m2.an
- Urban network
- Water radiator
- Radiant ceiling
- Solar thermal
- Urban network
- Solar Thermal
- No cooling system
- Natural ventilation
- Double flow heat exchanger
- Solar Thermal
- Other, specify
- 3 436,00 m2
- 48,00 %
- 1 137,00
- Urban heat island
- Building of passive design : this makes it possible to limit heating needs by minimizing losses as well as avoiding overheating in summer while benefiting from free solar contributions in mid-season.
- Straw insulation with an R of 9 : the use of this material limits heating needs in winter and keeps you cool in summer.
- Natural ventilation with heat recovery : no electricity consumption to ventilate the building, maintenance is simple and it is a solution that lasts over time.
- Overventilation at night, ceiling fans : low-tech cooling.
- Kindergarten playground without bitumen and partially green roofs : avoids the heat island effect.
- Massive stove as comfort and emergency heating in the event of a power cut.
Natural ventilation with heat recovery
La solution a été conçue par la direction recherche et innovation, Rosny-Sous-Bois et diffusée en partenariat avec le BET Switch.
Ville de Rosny-sous-Bois, BET Switch
Génie climatique, électricité / Ventilation, rafraîchissement
We are proposing a project that implements an innovative ventilation system which seems to us to be an appropriate response to the current challenges of controlling energy performance at a controlled technological cost: natural ventilation with heat recovery (VNRC).
The system is based on the use of plate heat exchangers in a natural ventilation network. Properly sized, the exchangers recover approximately 50% of the heat from the extracted air and generate acceptable pressure drops.
The originality of the solution lies in the fact that, unlike most natural ventilation strategies which are based on sweeping between an air intake in the lower part and an outlet in the upper part, we implement ventilation paths supply and extraction so that these flows intersect, thus allowing the implementation of heat recovery.
This diagram works if the network is sized sufficiently generously so that the pressure drops induced by the plate heat exchanger remain acceptable; in this case, the pressure differences due to the temperature differences and the action of the wind make it possible, on average, to achieve the expected air renewal.
The implementation of this system supposes the reversal of several solidly established practices concerning the ventilation of tertiary buildings:
• Consider ventilation as a stakeholder in the architecture, integrated into the building, rather than as an independent technical installation, constituting an added layer of distribution ducts.
• Giving users a hand in simple management of air renewal rather than automating the management of a complex installation.
• Aim for overall energy performance of the system rather than just thermal efficiency – in fact, mechanical ventilation installations with heat recovery have thermal efficiency close to 90% but generate significant electricity consumption. The VNRC developed here shows lower thermal efficiency (~50) but has no power consumption for air movement.
• Design a system on a statistical air quality target, based on CO2 concentration, rather than a flow rate target. Current regulations concerning mechanical ventilation are based on achieving air change rates. Natural ventilation is by nature unstable because it constantly balances itself according to internal and external climatic conditions; the air renewal flow is therefore not guaranteed continuously, it must therefore be resonated statistically and in terms of air quality (on the criterion of CO2 concentration) rather than on flow control.
This system was developed, probably for the first time in France, at the Boutours kindergarten in the municipality of Rosny-sous-Bois, by the City's internal project management unit. The Simone Veil school is the 3rd school project on which the VNRC system has been implemented; the design and implementation have reached a certain maturity. Furthermore, the instrumentation and monitoring of previous projects demonstrated the satisfactory operation of the system.
The Simone Veil school is developing this system on a large scale – it is a school of 11 classes – illustrating the replicability of the system.
Users of school facilities equipped with natural ventilation in Rosny-sous-Bois have integrated this new low-tech technology well, appreciating the thermal comfort of these new buildings compared to the existing aging stock. Simple indicators allow them to know the concentration of CO2 in the classrooms and activity rooms, and the teams are supported by the research and innovation department in handling these buildings.
Reproductibility and Innovation
- Construction principles and materials :
- solid oak structure with lattice beams and keyed beams;
- locally prefabricated facade boxes, wooden frame, straw filling and plastic-free double-sided earth coating;
- interior partitions in clay plates;
- solid oak furniture.
- Water and Energy :
- natural ventilation with heat recovery;
- sloping green roof;
- vegetated and permeable courtyard;
- mass stove;
- outside biocontrolled litter toilets;
- natural water retention basin.
- Citizen involvement:
- installation of logs to create outdoor games;
- educational garden;
- citizen participatory sites of burnt wood;
- wood recognition training.
- Final report Reflex Wood-Biosourced, 2021 (IDF Region): pdf here .
- Research VNRC 2022 (ADEME): Report to come.
Indoor Air quality
Reasons for participating in the competition(s)
The project presented responds to our constant concern to build buildings with the least possible impact on the environment , responding to the most pessimistic forecasts as to the evolution of the climate and the most low-tech maintenance possible. It is therefore a project by nature very resilient.
The hazards identified in Rosny-sous-Bois are mainly those of dense urban communities: increasingly present periods of heat waves , increasingly strained and expensive energy supply flows, drinking water management.
For this trophy, we are particularly highlighting an innovative ventilation system which seems to us to be an appropriate response to the current challenges of controlling energy performance at controlled technological cost: natural ventilation with heat recovery (VNRC).