Pamiers: 350 Homes and Public Buildings Connected to a Collective Wood Boiler
In Pamiers, Ariège, an investment of €1.20 million has just transformed a former gas boiler room into a biomass installation. The Castella high school, the Youth Center, the Town Hall and 350 homes now benefit from a heating network powered by wood pellets. The objective is twofold: reduce the energy bill by 20% and rely on a local Ariège supply chain.
The fuel comes exclusively from the company Kwbois in Saint-Paul-de-Jarrat. A local approach that avoids long-distance transport and guarantees a stable supply.
A Collective Wood Boiler Room to Replace Gas
A Large-Scale Project in a Constrained Space
From the street, nothing reveals the presence of this installation. A simple metal door in a parking lot leads to a staircase that descends to the machine room, installed underground.
Inside, pipes run along the walls and ceiling. Three pellet boilers are aligned. Behind a metal hatch is the combustion chamber that supplies heating and domestic hot water to the entire network.
Pascal Giraud, general director of Alliaserv, the company that financed and designed the system, explains: "We transformed this boiler room that operated exclusively on gas. The biggest difficulty was taking into account the equipment's bulk and installing everything in a constrained space."
The system includes three pellet boilers. Each can take over if necessary. The system also treats fumes, making the installation cleaner than with gas.
Ariège Pellets in a Local Supply Chain
The supply is entirely from Ariège. The pellets come from Kwbois, in Saint-Paul-de-Jarrat, a few kilometers from Pamiers.
This local supply chain has several advantages. It reduces the carbon footprint related to transport and guarantees better cost control. Local actors control the production and delivery of fuel.
For a territory like Ariège, this approach strengthens energy sovereignty. Wood is a local, renewable resource that is sustainably exploited.
20% Savings: The Argument That Convinced Stakeholders
A Reduced Energy Bill for Everyone
Alliaserv contractually commits to a 20% reduction in heating and domestic hot water bills. This commitment applies to all network users: owners, tenants and public managers.
Yves, owner of an apartment connected to the network, testifies: "This project attracted us because it ticks many boxes. Financial savings for owners, and then it corresponds to a heating method that better fits the modern world and the challenges of ecological transition. We felt we were dealing with a solid project."
Thierry Tourtoulou, director of the Ariège Public Housing Office, confirms: "We supported this project because obviously, there are savings to be made on charges for our tenants. Energy sovereignty, local supply chains: this project aligns with today's needs."
The Public Housing Office is also working on a major renovation project for its housing stock, with an investment of €7 million. The energy renovation of buildings complements the improvement of the heating system.
A Strategic Issue for the Occitanie Region
The Occitanie Region had to bear an additional cost of €100 million after the energy crisis linked to the war in Ukraine. High schools, major energy consumers, were particularly affected.
Kamel Chibli, vice-president of the Occitanie Region in charge of education and youth, emphasizes: "The high school is a major energy consumer. We had to face this additional cost because we don't control energy production."
The Castella high school welcomes several hundred students. Connection to this heating network reduces energy expenses and regains control over production.
For Kamel Chibli, this project is exemplary: "We are shareholders. We are consumers of this energy produced with local supply chains. An example to follow."
Buildings Concerned and Future Extensions
Current Users of the Heating Network
The network currently supplies several types of buildings:
- 350 homes, including part of the Ariège public housing stock
- The Castella high school, which has several hundred students
- The Youth Center of Pamiers
- The Town Hall of Pamiers
This pooling between housing and public buildings optimizes the boiler room's operation. The more users the network has, the more profitable the installation.
Future Connections Under Consideration
Several extension projects are under study. The Rambaud middle school, located nearby, could join the system soon.
The Region is also examining the possibility of connecting the health professions training school, located near the city's former hospital.
These extensions would increase the number of beneficiaries and strengthen the installation's profitability. The economic model is based on pooling: the more subscribers, the lower the unit cost.
A Model to Follow for Other Communities
Lessons from the Pamiers Project
The Pamiers project demonstrates that a conversion from gas to wood is technically feasible even in an existing space. The underground installation preserved the use of the land above ground.
Pooling between housing and public buildings is economically relevant. It guarantees constant demand and allows costs to be smoothed out.
The local supply chain is a stability factor. By sourcing locally, managers avoid price tensions and risks related to long-distance transport.
Consistency with Energy Renovation Policies
The Ariège Public Housing Office is investing €7 million in the energy renovation of its housing stock. Building insulation and heating system improvement complement each other.
A well-insulated building consumes less. An efficient heating system further reduces the bill. The two levers combined allow real control of charges for tenants.
For owner-occupants connected to the network, the 20% savings are added to gains from any insulation work.
What You Can Learn from This Initiative
Wood Heating Networks, a Credible Alternative to Gas
A heating network operates on a simple principle: a central boiler room produces heat, then distributed via a pipeline network to subscribed buildings.
Advantages for users:
- No individual boiler to maintain
- Billing based on actual consumption
- Better price stability than with gas or fuel oil
- No heavy initial investment
On this type of project, observed savings can reach 20% on the energy bill. The gain depends on the fuel replaced and the installation's performance.
Check If Your Municipality Has a Heating Network
Contact your town hall or social housing provider to find out if a heating network is in service or planned in your area.
Find out about the type of fuel used: wood, biomass, geothermal. The origin of supply also matters. A local supply chain guarantees better price control.
Compare the connection cost and subscription to your current solution. Request a simulation for a full year, including heating and domestic hot water.
Grants for Collective Biomass Boiler Rooms
Communities and housing providers can mobilize the ADEME Heat Fund to finance part of the investment. This program supports renewable heat production projects.
Individuals connected to a heating network benefit indirectly from price optimization. The manager passes on the savings to subscribers.
If you are considering an individual installation — wood boiler, pellet stove — check your eligibility for MaPrimeRénov' and Energy Savings Certificates (CEE). Both programs can be combined under conditions. The contractor must be RGE certified. Procedures must be initiated before work begins.