A masonry heater is not just for houses. Six masonry heaters heat five school facilities in a single municipality, Rosny-sous-Bois — two school groups, an eco-school, a nursery school and a leisure centre — in buildings that rank among the best-documented eco-construction schemes in Île-de-France.
What a heater brings to a public building
Let’s say it straight away: it does not heat the building. A school covers several thousand square metres and is heated by a network — in Rosny, a geothermal district heating network. The masonry heater serves three other purposes there, and those are why it is chosen.
A heat source that depends on nothing. No electronics, no pump, no wearing parts: the technical file for the Mermoz school group classes the heater among its ‘low-tech, low-complexity systems’. In a network outage or breakdown, it keeps working with wood and a match.
Back-up heating that cuts mid-season consumption. One burn a day in a covered playground or activity room covers the needs of mild days, when starting up the main system costs a lot for very little.
A teaching tool. In a school, a fire visible behind glass, a warm mass to sit against and wood that is carried in by hand: these things can be explained and shown. It is often the argument that wins the teams over.
What public procurement means on our side
We bid for public contracts as a separate lot: at the Mermoz school group it was lot no. 14, ‘Poêle de masse’ (masonry heater). This calls for a different way of working from a project in a private customer’s home.
A design calculation justifies the sizing, room by room, and accompanies the bid. The schedule is that of the overall site, with its weekly progress reports and coordination between lots — the roof penetration, clearances to timber and the openings to be left are decided with the project manager, not on the spot. Handover is recorded in a formal acceptance report, and reservations are lifted formally.
In Rosny, project management is in-house: it is carried out by the town’s Research and Innovation department. We therefore worked directly with the technical services, with no lead architect — a demanding set-up, in which you have to defend your technical choices before people who check them.
Our public-sector references
Groupe scolaire Jean-Mermoz (school group) — delivered in 2024, nearly 3,800 m², load-bearing straw, raw earth bricks and solid chestnut.
École maternelle du Bois-Perrier (nursery school) — thermal renovation, straw insulation, natural ventilation by wind towers.
Éco-école des Boutours (eco-school) — new build in load-bearing straw and raw earth.
Groupe scolaire Simone-Veil, formerly Métropolitain — one masonry heater, contract as a separate lot (lot no. 16).
Centre de loisirs Jacques-Chirac (leisure centre) — new building with timber frame and timber cladding.
Contact us
For a consultation, a lot to be costed or a feasibility study ahead of a programme, write to us: we provide a design calculation and detailed costing, and we know how to work with a project manager.
Sources
- Fiche d’opération « Groupe scolaire Jean Mermoz » (project sheet) — Ekopolis
- Fiche d’opération « Groupe scolaire Les Boutours 2 » (project sheet) — Ekopolis
- Fiche d’opération « École maternelle Bois-Perrier » (project sheet) — Ekopolis
- « Terre crue et paille dans les nouvelles écoles de Rosny-sous-Bois » (Raw earth and straw in the new schools of Rosny-sous-Bois) — Banque des Territoires
- « Les écoles de Rosny-sous-Bois écoconstruites grâce à une maîtrise d’œuvre internalisée » (Rosny-sous-Bois schools eco-built thanks to in-house project management) — Le Moniteur