DE
am 19.08.2024 - 09:46 Uhr
Requirements based on direct wording in the legal text
The actual legal text of the Building Energy Act GEG 2024 lists several requirements for building automation (BA). The key section is “Section 71a Building automation”, which in turn is included in the section “Requirements for a heating system”. The requirements have practical consequences.
§ Section 71a “Building automation”
Non-residential buildings in existing buildings with a heating or air conditioning system with a rated output of more than 290 kW must be equipped with energy monitoring technology that provides data via a standard and freely configurable interface to an energy management system by the end of 2024. A “building automation and control system” must also be introduced. Unfortunately, the legal text leaves room for interpretation as to whether this requires “automation level B” in accordance with DIN V 18599 “Energy performance of buildings - Calculation of the useful, final and primary energy demand for heating, cooling, ventilation, domestic hot water and lighting - Part 11: Building automation” (09/2018) or whether a BA functionality must be demonstrated in some other way (see later section “Legal interpretations”).
Non-residential buildings in existing buildings with an existing BA system of automation level B or better must demonstrate the ability to communicate across manufacturers by the end of 2024.
Newly constructed non-residential buildings must be equipped with a BA system of automation level B or better. In this respect, it is legally interpretable whether this applies to all non-residential buildings or only to the large ones (rated output of the heating/air conditioning system > 290 kW) (see also later section on legal interpretations).
The following also applies to affected buildings:
- Commissioning must include a heating or cooling period.
- It must be ensured that communication between the technical building systems and the applications is possible even with different proprietary technologies and devices.
This paragraph 71a places considerable demands on building automation. Firstly, the buildings concerned must achieve automation level B or better (in accordance with DIN V 18599 Part 11). The resulting requirements will be discussed in more detail later.
An interesting requirement is that the commissioning of an automation system for heating or cooling must cover an (entire) operating period. It is therefore not sufficient to commission the automated system for heating in summer and for cooling in winter. This also rules out selective commissioning, for example within a day or a week.
In addition, the requirement for cross-manufacturer and cross-technology communication of all (!) technical building systems and applications must be classified as essential. This requires the use of standardized protocols - not only externally, but also internally between the systems and applications!
In addition, there is an obligation to retrofit energy monitoring technology for the affected buildings with heating/cooling capacities over 290 kW by the end of 2024. [Explanation: As explained later, the BMWK only “wanted” the retrofitting obligation for EÜD for existing buildings - but not GA. If you reduce it to this, the requirement can very well be implemented]
§ Section 60b “Testing and optimization of older heating systems” (paragraphs (1) and (2))
This paragraph deals with the testing of vacation reduction and presence control in heating systems, unless the heat is generated by heat pumps.
Initially, this requirement applies to residential buildings with more than six residential units or non-residential buildings with more than six independent user units. The requirement stipulates that a heating system inspection and optimization must take place from the 15th year of operation following the installation of the system. Vacation reduction and presence control are also part of the inspection. For systems installed before October 1, 2009, this inspection must have taken place by September 30, 2027. If an inspection has to be carried out, a one-off inspection is sufficient.
The legal text initially only requires an inspection and not necessarily the existence of a vacation setback. The buildings concerned are assumed to be used by different parties. It is therefore unlikely that usable vacation or individual absence times, as could be recorded via room automation, will result for central heat generation. The tests could show that it is sufficient from an efficiency point of view to carry out a night or summer shutdown. However, these requirements can be stored in the heat generator control system and do not result in any requirements for the overarching building or room automation system.
§ Section 60b “Inspection and optimization of older heating systems” (paragraphs (7) and (8))
This paragraph contains the omission of the obligation to test heating systems if a standardized BA system exists in accordance with Section 71a.
The heating inspection and optimization previously included in § 60b can be omitted if a BA system exists, provided that this essentially corresponds to automation level B or better in accordance with DIN V 18599 Part 11 and uses standardized protocols. If this exemption from the obligation is claimed, project documents must be submitted in a verifiable form.
Even if a corresponding GA system is in place, it still makes sense to check and optimize the heating system. After all, this is a one-off inspection after an operating period of more than 15 years. It is therefore questionable whether this waiver of the obligation should be or will be used.
§ Section 74 “Energy inspection - operator obligation” (paragraph 3)
This concerns the elimination of the obligation to inspect air conditioning systems if a standardized BA system exists in accordance with Section 71a.
Section 74 regulates inspection obligations for air conditioning systems with an output of more than 12 kW; these are subject to an inspection interval of ten years. The inspections can be omitted if a BA system is in place, provided this corresponds to automation level B or better in accordance with DIN V 18599 Part 11 and uses standardized protocols.
Reference is made to § 71a (5). This paragraph no longer exists as it has since been moved to paragraph (2) (“Energy monitoring technology”).
Even if a corresponding GA system is in place, it still seems sensible to check the air conditioning system and inspect it every ten years. It is therefore questionable whether this exemption from the obligation should be used or is used.
Requirements based on the degree of automation
The degrees of automation are defined in DIN V 18599 Part 11 and are shown below. This is done with a focus on non-residential buildings and on precisely those requirements for which a degree of automation B or A is specified.
The following diagrams show the automation requirements for different trades (heating, cooling, ventilation, lighting/shading and technical building management). Whether the aspects of all trades or all questions of a trade must be fulfilled for legal compliance will be dealt with later. At this point, the focus is initially on what is meant by “automation level B or better” in accordance with DIN V 18599 Part 11.
Source: Prof. Krödel on the basis of DIN V 18599-11:2019
In order to comply with the law, all the requirements listed in the diagrams must be met. Individual requirements may be omitted if “the designer can sufficiently justify that the application of a function in a particular case does not bring any benefit.” This exception is not described in DIN V 18599 Part 11, but in DIN EN 15232 “Energy efficiency of buildings - Part 1: Influence of building automation and building management” (12/2017), to which DIN V 18599 refers. If corresponding exceptions are used, it is important that these are not formulated in general terms, but in concrete, verifiable terms.
Legal interpretations
Aspect 1: Requirement “automation level B or better” for existing buildings?
Laws should be clear and unambiguous. The fact that this is not always the case is shown by the many disputes that have been brought before the courts. The Federal Ministry of Economics and Climate Protection (BMWK) has issued a statement on the legally unclear aspects of the GEG. Unfortunately, this begins with the clarification that the statement is not legally binding and can only serve as a guide. The BMWK's statement thus shows what was “desired” or “meant” and the assumption arises that the legally interpretable requirements will not be checked and punished by the authorities. However, this is not entirely certain, and there is still the risk that the building owner or the client of a new construction or renovation project will sue for subsequent performance free of charge for a legally interpretable requirement. Planners in particular should be aware of this risk!
In order to be able to “grasp” the requirements nevertheless, the following is divided into the undisputed requirements on the one hand and the legally interpretable requirements on the other; this means that a distinction can at least be made between a “lower limit” and an “upper limit” of the requirements. As a precautionary measure, the author would like to point out that this presentation is made to the best of his knowledge and belief and therefore without any liability.
Aspect 2: Overview of the requirements
The following table shows an overview of the requirements. A tick stands for a clear requirement to be fulfilled. The question marks are placed where there is room for legal interpretation. Where a slash is entered, there are no requirements.
Existing non-residential buildings:
If the rated output of the heating/air conditioning system in an existing building does not exceed 290 kW, no requirements need to be observed. If this threshold value is exceeded, energy monitoring technology including data exchange via company and manufacturer-independent interfaces must be ensured in any case. It is unclear whether “automation level B or better” must then also be implemented.
According to the BMWK, this is not the case. Unfortunately, the BMWK's statement begins by stating that this can only be seen as “understanding” and “orientation” and may be judged differently in court. A reliable and legally sound statement sounds different. As a consequence, this level of automation should be largely used as a guide, especially for renovations and conversions, or, in case of doubt, an energy consultant or planner should be consulted to confirm why the introduction of the respective automation functions is not economically viable.
New non-residential buildings:
If the nominal output of the heating/air conditioning system in a new building exceeds 290 kW, automation level B and cross-system and cross-manufacturer communication between all technical building systems and applications must be clearly guaranteed.
If this threshold value is not reached, the question arises as to whether the listed requirements also apply. According to legal assessments of the exact wording in the law, this also applies. However, the BMWK's understanding is different: that the degree of automation only applies to “large” new non-residential buildings. As mentioned, the BMWK's statement begins by stating that this should only be seen as an “understanding” and “orientation” and may be judged differently in court. Here, too, it is advisable to follow the guidelines unless you can document in writing why it is not economically viable to apply them.
Scope of the requirements for “automation level B or better”
If the “degree of automation B or better” must be implemented in accordance with DIN V 18599 Part 11, the question arises for which trades and to what extent this must be ensured. It is initially undisputed that the heating trade is affected and, in the case of an air conditioning system > 290 kW, the cooling trade is also affected.
However, it is legally unclear whether the automation requirements also affect the other trades (ventilation, lighting/shading and technical building management). The BMWK's understanding of this is that if “automation level B or better” is required, all trades are actually affected! If you consider what this means (presence-based dimming function for lighting in every room; slat tracking for blinds in every room), the question arises as to whether the legislator is aware of the consequences and the practical sense of these requirements and measures.
If all trades actually have to fulfill the “automation level B or better”, there are still exceptions to be made. Firstly, DIN V 18599 Part 11 states:
“If the influence of an automation function has less than a 5 percent share of the total energy demand, this function is not decisive for the classification of the overall degree of automation”.
This means that an automation function can be ignored if a correspondingly comprehensible and verifiable calculation can be made. It is important to note that this should be done using calculations by a specialist planner or energy consultant - a calculation using energy performance certificate software is not sufficient (as this does not correctly take into account the influence of building automation). If corresponding exceptions are used, it is important that these are not formulated in general terms, but in a concrete and verifiable manner.
Conclusion:
The GEG 2024 contains considerable requirements, particularly for building automation in the heating and cooling trade. Due to several legally unclear formulations, these can be divided into undisputed and legally interpretable requirements. For all requirements, however, they should not be ignored, but dealt with.
In conclusion, the author refers to the B-CON software from ICONAG-Leittechnik GmbH in Idar-Oberstein for the implementation of the requirements: “With regard to the requirements for energy monitoring technology and the higher-level control functions, I consider the B-CON system to be suitable for implementing them in full.”
Dr. Michael Krödel is Professor of Building Automation and Technology at Rosenheim University of Applied Sciences and Managing Director of the Institute for Building Technology. He is also a registered energy consultant (“dena energy efficiency expert”), a member of the VDI guidelines committee for VDI 3814 (building automation), the jury for the SmartHome Initiative Award and on the scientific advisory board of the Gebäudeenergieberater Ingenieure Handwerker-Bundesverband e.V. (GIH).
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