EcoDesign and Class 5: what your building permit file must prove

Why must the permit file already prove EcoDesign compliance?

The permit review doesn't wait until commissioning to check compliance. Drawings and the technical note must already name the boiler, its standard and its performance figures.

An incomplete file slows down the review and complicates access to subsidies later.

What EcoDesign Regulation (EU) 2015/1189 requires

Since 1 January 2020, every solid-fuel boiler placed on the market must meet efficiency and emission thresholds. These thresholds appear on the manufacturer's data sheet and belong in the permit file.

• Seasonal space heating energy efficiency of at least 75% up to 20 kW, and at least 77% above 20 kW (Regulation (EU) 2015/1189, Annex II)
• Particulate emissions capped at 40 mg/m³ for automatic feed, 60 mg/m³ for manual feed
• Gaseous organic compounds limited to 20 or 30 mg/m³ depending on feed type
• Carbon monoxide limited to 500 or 700 mg/m³, nitrogen oxides capped at 200 mg/m³ for biomass boilers

EN 303-5 Class 5 and pellet quality: two pieces of the file

EN 303-5 governs performance testing for solid-fuel boilers, and Class 5 is its most demanding tier. The permit file is stronger when it includes the boiler's certificate and a reference to the pellet quality standard.

• Require the manufacturer's EN 303-5 Class 5 certificate, attached to the technical note
• Specify ENplus A1 certified pellets: diameter 6 ± 1 or 8 ± 1 mm, moisture content of at most 10%, ash content of at most 0.7%, net calorific value of at least 4.6 kWh/kg
• Note that ENplus A2 (ash ≤ 1.2%) and B (ash ≤ 2.0%) grades exist but are lower quality than A1
• Reserve space for a buffer tank from the sketch stage — technical files often request it

Compliance and the Klimabonus: a coherent file opens the door to subsidies

The 2026 Klimabonus for a pellet boiler has its own technical criteria, close to but not identical with EcoDesign. Anticipating them in the permit file avoids a second round of paperwork later.

• The Klimabonus requires controlled combustion, automatic feed and ignition, and connection to a central heating circuit
• Dust emissions capped at 8 mg/m³, nitrogen oxides at 200 mg/m³, production efficiency of at least 90% (source: guichet.public.lu)
• The claim must be filed within 4 years of 31 December of the invoice year
• The amount can reach €8,000 for a single-family home (€4,000 without replacing an old installation), or €6,000 per unit in a collective building, capped at €40,000; a 15% bonus applies with a buffer tank of 30 l/kW, and a flat €1,000 bonus with solar thermal (source: guichet.public.lu)
• Communal aid varies from one municipality to another and can stack with the Klimabonus; some municipalities offer nothing