New collective housing in Luxembourg: pellets or wood chips, how to design the boiler room?
Architects: compare pellets and wood chips for a new collective project in Luxembourg, size the silo and buffer tank, and secure Klimabonus 2026.
Pellets or wood chips for a new collective housing project in Luxembourg: what does Klimabonus 2026 actually fund?
For a new collective building in Luxembourg, only a wood-pellet boiler qualifies for Klimabonus 2026. Wood chips receive no state grant, even though they remain technically viable.
The grant reaches up to €6,000 per dwelling, capped at €40,000 per project. Add a +15% bonus with a buffer tank, and a flat €1,000 when the project also includes solar thermal.
- Amount: up to €6,000/dwelling, capped at €40,000
- Buffer tank bonus: +15%, solar thermal bonus: flat €1,000
- Municipal grants: stackable but variable by commune
Silo and buffer tank: what dimensions to lock in at the APS stage?
For one year of autonomy, size the silo at 4–6 m³ per dwelling and plan the blower-truck path: DN50 connection, ≤ 30 m distance, inspection hatch accessible from the public road.
The buffer tank should hold 20–30 L/kW of installed capacity: it smooths the cycles, extends boiler life, and unlocks the +15% Klimabonus bonus.
- Silo access ramp: ≤ 15% slope, ≥ 1.2 m wide
- Boiler room: ventilated, frost-free, with safety shut-off
- ENplus certification mandatory for delivered fuel
Seasonal efficiency and maintenance: what does the regulation require?
EU Regulation 2015/1189 (EcoDesign) has set, since 2020, minimum seasonal efficiency and emission ceilings for every biomass boiler ≤ 500 kW. The EN 303-5 Class 5 standard remains the product benchmark.
A modern pellet boiler delivers 85–92% seasonal efficiency. From sketch stage, plan technician access for annual servicing, ash removal, and storage of wear parts.
- EcoDesign EU 2015/1189: applies to every biomass boiler ≤ 500 kW
- EN 303-5 Class 5: product benchmark for efficiency
- Maintenance hatch: 80 × 80 cm minimum recommended
Pellets vs wood chips in collective housing: the logistics logic that decides
Wood chips require 3× more storage volume, are sensitive to moisture, and arrive by tipper truck — three deal-breakers in dense urban areas.
ENplus pellets offer stable energy density, clean blower-truck delivery, and above all Klimabonus eligibility. For a new collective project in Luxembourg, this is the option that aligns economics, logistics and compliance.
- Wood chips: not eligible, 3× larger silo, variable moisture
- Pellets: Klimabonus-eligible, ENplus, blower truck
- Tatano: pellet range up to 500 kW for collective projects
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