BACS Requirements in Germany

The requirement comes from Directive (EU) 2024/1275, the recast Energy Performance of Buildings Directive (EPBD). Article 13 mandates that EU member states require non-residential buildings to equip relevant technical building systems with building automation and control systems where technically and economically feasible.

In Germany, the EPBD is transposed through the Gebäudeenergiegesetz (GEG) — the Building Energy Act. The GEG consolidates earlier regulations (EnEV, EEWärmeG) and is the primary legal instrument for building energy performance requirements. Updates to the GEG to reflect the 2024 EPBD recast are expected through federal implementation measures.

The technical standard referenced for BACS classification is EN ISO 52120-1 (formerly EN 15232), which defines four BACS efficiency classes (A through D). Class C is the minimum acceptable level under the directive — buildings with Class D systems or no automation are the primary targets for mandatory upgrade.

The BACS requirement applies to non-residential buildings where the effective rated output of the relevant technical building systems exceeds the threshold. In Germany, this includes:

• Office buildings and commercial premises
• Retail and shopping centres
• Hotels and hospitality
• Hospitals and healthcare facilities
• Schools, universities, and public buildings
• Logistics centres and warehouses with conditioned space
• Industrial buildings with significant HVAC load

Residential buildings are excluded from the BACS mandate. Mixed-use buildings are assessed based on the non-residential portion.

The "effective rated output" refers to the combined capacity of heating, ventilation, air conditioning, and hot water systems serving the building. A building with a 120 kW heating system and a 60 kW cooling system has an effective rated output of 180 kW and falls within the >70 kW threshold.

A compliant building automation and control system must, at minimum, achieve EN ISO 52120-1 Class C or better. This means the system should be capable of:

• Continuous monitoring of energy consumption
• Benchmarking against expected performance
• Detecting faults, losses, and efficiency drift
• Providing actionable information to operators
• Enabling demand-based control of HVAC systems

A basic timer-based BMS or standalone thermostats do not meet the requirement. The system must actively monitor, report, and support optimisation — not just switch equipment on and off.

Germany has the largest non-residential building stock in the EU. Key facts for building owners and consultants:

• GEG (Gebäudeenergiegesetz) is the transposing legislation. Amendments reflecting the 2024 EPBD recast are expected to formalise BACS obligations at national level.
• BAFA (Bundesamt für Wirtschaft und Ausfuhrkontrolle) administers energy efficiency funding programs including BEG (Bundesförderung für effiziente Gebäude) which can offset BACS upgrade costs.
• dena (Deutsche Energie-Agentur) maintains the energy efficiency expert registry and publishes guidance on building automation.
• Energy audits under the EDL-G (Energiedienstleistungsgesetz) already require large enterprises to audit every 4 years. BACS readiness is increasingly part of audit scope.
• KfW and BAFA grants can cover 15–40% of BACS upgrade costs depending on the program and building type.

1. Determine your HVAC rated output. Sum the effective rated output of all heating, cooling, ventilation, and hot water systems. If it exceeds 70 kW, you are in scope for 2029.
2. Assess your current automation level. Do you have a BMS? Does it monitor, detect faults, and report to operators? Or is it just timers and thermostats?
3. Check available funding. BEG programs through BAFA and KfW can significantly reduce net investment. Apply before the 2029 rush.
4. Plan the upgrade path. A phased approach — monitoring first, then optimisation — is often more practical than a full BMS replacement.
5. Document everything. Evidence of compliance (system diagrams, trend logs, commissioning records) will be needed when enforcement begins.