Requirements of the Building Energy Act (GEG 2024) for building automation

After the previous articles in this series on the technical implementation of the requirements of the German Building Energy Act (GEG) explained the general technical requirements (see cci273251) and the trades of cooling and ventilation systems (see cci275128), this article focuses on how the provisions of Section 71a should be specifically interpreted and implemented in terms of energy and building automation management.

Equipping with Digital Energy Monitoring Technology

For the heating and/or cooling of non-residential buildings with a thermal output exceeding 290 kW, §71a of the German Building Energy Act (GEG) mandates the installation of digital energy monitoring technology, which enables:

• Continuous monitoring, logging, and analysis of the consumption of all primary energy sources as well as all building technology systems.
• The establishment of target values related to energy efficiency.
• The detection of efficiency losses in building technology systems.
• The ability to inform the responsible management personnel about potential energy efficiency improvements.

Continuous Monitoring and Energy Efficiency

The required monitoring technology must digitally read not only the main meters but also the meters of all building technology systems. Since §71a defines requirements for heating systems, "all" is likely intended to include separate submeters for energy-consumption-intensive systems such as heating, hot water, ventilation, and cooling. These systems must be equipped with remotely readable meters, for example, with M-Bus, ModBus, or LoRa interfaces, and the data must be recorded and stored via software. The legislator does not explicitly define these requirements and unfortunately refrains from providing further details.

To enable digital monitoring technology to establish and track target values related to energy efficiency, the system must allow the generation and monitoring of key performance indicators (KPIs) as efficiency benchmarks. In addition to pure metering data, the system must also record and store information such as indoor and outdoor temperatures, as well as supply and return temperatures of HVAC systems. Furthermore, it must provide the capability to define reference areas for energy consumption. Details on this topic can be found in the guide "Energy Management in Municipalities. A Practical Guide," published by KEA Climate Protection and Energy Agency of Baden-Württemberg GmbH, Karlsruhe. Only with concrete numerical data can the actual energy efficiency of systems be determined, and potential efficiency losses identified by comparing them with expected target consumption or benchmarks from similar buildings.

Generating Automatic System Notifications

A key requirement of the law is that responsible personnel must be informed about potential improvements through the energy monitoring technology. To achieve this, the system must be capable of generating notifications and capturing not only consumption data but also information about system conditions. Additionally, it should provide insights into how systems currently interact and what optimizations can be made.

The necessary functions—such as alarm and event management, trend analysis, and system visualization—can be integrated into building automation management via a management and control interface. The legislator's requirement that the collected data be accessible through a common and freely configurable interface is best met at the management level using standard office software interfaces such as CSV or Excel.

It is not explicitly specified whether the management and control interface, along with the energy management system, must be physically installed within the building or if it can be integrated into a central control system or cloud-based solution. Therefore, both approaches are likely permissible.

Based on this interpretation, the overview presented by Prof. Michael Krödel in his article "Requirements of the Building Energy Act (GEG 2024) for Building Automation in Heating and Cooling" can be further specified regarding the requirements for "energy monitoring technology" and "building automation systems," as illustrated in Figure 2.

It is advisable to integrate smaller non-residential buildings into energy management

Even non-residential buildings with a thermal connection load of less than 290 kW, equipped with an automation system of at least level B (see the white paper "The Legal Requirements of GEG 2024 for Building Automation" by Prof. Krödel), should be managed via a management and control interface with an energy management system. This can, for example, be achieved by integrating them into a central system managing multiple properties.

Personnel Requirements

Beyond the technical requirements for energy monitoring, the German Building Energy Act (GEG) also stipulates that "a person or company responsible for building energy management must be designated or commissioned to continuously identify and implement energy optimization potentials for building operation as part of an ongoing improvement process."

This poses a significant challenge for many operators, particularly because technical facility management is often assigned to janitors in many organizations. Typically, janitors are not specialists in heating, ventilation, or cooling systems and are not trained for energy-optimized building operation. Their primary concern is ensuring a smooth and user-friendly operation rather than optimizing energy performance.

For most buildings and real estate portfolios, meeting this requirement will only be feasible through a centralized approach to technical facility management. Whether organizations establish an internal department with access to all buildings via a central energy management system with building automation (MBE or GLT) or outsource operations to external service providers is left to their discretion.

Practical Example: Centralized Energy Management Enhancing Efficiency

A successful example in the municipal sector is Energiedienstleistungsgesellschaft Rheinhessen-Nahe GmbH. Founded in 1998, this organization consolidates the energy management of properties belonging to the districts of Mainz-Bingen, Alzey-Worms, and Bad Kreuznach, along with several municipal associations. By transferring responsibility for the energy-efficient operation of public buildings to a publicly owned entity, a foundation for continuous energy efficiency improvements was established. Additionally, decentralized energy supply structures were implemented.

Conclusion

In summary, the GEG aims to ensure the energy-efficient operation of non-residential buildings through specific and enforceable requirements. According to the latest version of the Energy Performance of Buildings Directive (EPBD), these requirements will also apply to non-residential buildings with a thermal connection load of 70 kW starting in 2030. As an EU directive, this threshold will be incorporated into future versions of the GEG.

Ultimately, implementing the requirements of §71a of the Building Energy Act is crucial to achieving the climate targets set for the building sector by 2045.

Christian Wild is the Managing Director of Iconag Leittechnik GmbH in Idar-Oberstein, a software company specializing in manufacturer-independent building management systems, energy management, and digitalization in technical building management. Wild previously served for eight years as the head of the Rhineland-Palatinate-Saarland regional group of the German Facility Management Association (GEFMA) and is a member of the VDI guidelines committee for the revision of VDI Guideline 3814. Additionally, he is a lecturer in building automation at Mainz University of Applied Sciences and an active member of the Gutenberg Digital Hub in Mainz. (Fig. © Iconag)