VdS-Schadenverhuetung Technische Pruefstelle

Tasks, problems, solution strategies

What do experts actually do?

There are always discussions and misunderstandings about what the tasks of an expert are. The following article will take a closer look at the tasks and responsibilities.

Text: Frank Bieber, VdS Schadenverhütung GmbH, Deputy Head of the Technical Inspection Services

Let's get straight to the point: Not everything is clearly regulated and there are ambiguities in various places or the legal situation differs greatly from actual practice. This becomes clear when we start with the term “expert”. Who is that? A person with expertise. Of course. But otherwise this term is not protected. Anyone can call themselves an expert, there are no requirements.

The situation is different for inspection experts. For example, a “test expert in accordance with Section 4 (1) of the NRW Test Ordinance (PrüfVO NRW) dated November 24, 2009 (GV NRW p. 723), which came into force on December 28, 2009”, as stated in the author's certificate of recognition issued by the Düsseldorf district government. The legal basis and thus the formulations vary in the individual federal states, but in principle each federal state has an inspection expert for various fields of supply engineering. The tasks of the expert for fire extinguishing systems are described below.

What are the requirements for recognition as an inspection expert?

In general, you have to have an engineering degree to be recognized as an expert. Safety engineering, mechanical engineering, civil engineering, electrical engineering and supply engineering are classic courses of study here. In case of doubt, the admissibility of the course of study must be agreed with the body responsible for recognition in the respective federal state. In addition to the degree, five years of professional experience in the respective field of study must be proven, as well as sufficient liability insurance, access to the necessary measuring equipment and a certificate of good conduct without relevant entries.

Once these formal requirements have been met, proof of professional qualification must be provided in the form of an expert opinion. These certificates are issued by the Stuttgart Region Chamber of Industry and Commerce or the Brandenburg Chamber of Engineers. Not all federal states accept both bodies, but you can usually choose where you want to take the exam. The exam consists of a written and an oral-practical part.

The examination is not a sure-fire success and there are definitely relevant failure rates, which can increase the duration of these procedures to several years. After passing the examination, you can then be recognized as an inspection expert in the respective federal state. The individual federal states recognize each other's inspection experts, so you only have to go through the procedure once in the federal state in which you have your “main residence, place of business or predominant professional activity”.

Once you have obtained expert status, you will be included in a publicly accessible list or an online database in most federal states. In the following, the measures for quality monitoring vary greatly from state to state. Insurance certificates and/or test reports may have to be submitted regularly.

What are the tasks of the inspection expert?

Once approval has been granted, the question of rights and obligations arises. Depending on the federal state, automatic and non-automatic extinguishing systems must be tested before commissioning, after significant changes and at regular intervals (between one and six years, depending on the federal state and trade). The individual federal states do not generally specify what the expert does during the inspections themselves, but often (not always) refer to the “Principles for the inspection of technical systems in accordance with the Model Inspection Ordinance by inspection experts recognized by the building authorities (Model Inspection Principles)”. These provide a rough framework for the content of the inspection and report.

Unfortunately, the test principles are not really practical. In the case of automatic extinguishing systems, for example, there is no difference in content between a pre-commissioning test and a periodic test. Of course, this completely ignores practical requirements, as the entire hydraulic calculation will not be checked again at every test if nothing has changed in the extinguishing system. It is also not possible to check all sprinklers during periodic inspections because, for example, false ceilings or shelving systems are not fully accessible. In view of recent legal decisions, these principles will have to be considered[1], otherwise the time and effort required for inspections and therefore the costs will have to increase significantly. The model inspection principles clearly define the responsibility: “The inspection expert is responsible for ensuring that the type and scope of the inspections he carries out on the individual system are necessary and sufficient.”

In principle, the expert assesses the effectiveness and operational safety of the system by comparing it with a test basis.

What can be the basis for testing?

For this target/actual comparison, it is of course crucial which test basis is used for the comparison. Annex 14 of the model administrative regulation Technical Building Regulations (MVV TB) refers to EN 12845 : 2020-11 as the standard. This appears to be a reference to a current set of regulations. However, the standard is technically completely outdated. For example, the fire behavior of plastics is insufficiently considered. A new standard is currently being developed at European level in CEN TC 191/ WG5/TG2. This will represent a quantum leap in quality compared to the current version. However, it is not expected to be published before 2026.

Due to the deficits in terms of content, the author believes that the currently valid DIN EN 12845 should not be used as a basis for testing. However, the MVV TB also provides the option of specifying other test bases in the fire protection certificate. CEA 4001, FM Global Data Sheets and VdS CEA 4001 are cited here as examples. A new MVV TB was published on 17.04.2023 and corrected on 10.05.2023,[2] in which some - but not all - errors and ambiguities were corrected. In the federal states, however, the MVV TB must first be adopted in their own ordinances. The MVV TB from 2021 currently applies in most federal states. With the exception of DIN EN 12845, the test principles specified in the model administrative regulation are test principles under private law that have their origins in the insurance sector. As insurance companies have been dealing with the effectiveness of extinguishing systems for their risk transfer for much longer than building law, the origin of these regulations cannot be seen as a disadvantage.

[1] See also: Claas Baier, „Saunabrand: überraschendes Gerichtsurteil“, s+s report 4/2022, S. 26 ff

[2] See also:  s+s report 2/2023, S. 22 f 

As an expert, how do I confirm the effectiveness of an installation?

Essentially, the test expert compares the test basis with the installed system. Even if the inspector does not usually know personally whether a test basis is effective, the standards and guidelines specified above are to be regarded as the state of the art (possibly limited in the case of DIN EN 12845, see above) and the expert can assume that the effectiveness and operational safety can be confirmed if these regulations are complied with. It is important that the approved fire protection certificate or the building construction report clearly states the regulations according to which the system must be planned and constructed.

If deviations from the test basis are found during the test, these must be documented in the test report and, if necessary, deadlines for rectification must be set. The individual federal states have very different requirements as to how defects are dealt with. An expert has also been accused in court of adhering to the defect classification specified by the highest building supervisory authority of the federal state. This topic offers enough material for its own article[3].

[3] See also: Claas Baier, „Saunabrand: überraschendes Gerichtsurteil“, s+s report 4/2022, S. 26 ff

Wenn die Regelwerke keine Lösungen bieten

However, there are always construction projects where the circumstances present planners with challenges. For example, when storing flammable liquids, all of the aforementioned regulations may not offer any solutions for designing the extinguishing system.

Experienced planners or concept developers are then required. Extinguishing system concepts are developed on the basis of various regulations. This often results in high-quality concepts that have been created to the best of our knowledge and belief. The fact that cost pressure is sometimes the driving force behind extinguishing system concept solutions should not go unmentioned. Whether optimized for cost or effectiveness, the extinguishing system concepts are submitted as part of the fire protection concept with the building application and approved by the lower building supervisory authority (procedures according to the Federal Immission Control Act etc. are not mentioned here). The author is only aware of very isolated cases in which the approving authority has objected to details in the extinguishing system concept. As a rule, the concepts are approved.

What does the approving expert do now? The approved extinguishing system concept has been implemented and he/she should now certify the “effectiveness and operational safety” in the test report in accordance with the sample test principles. A dilemma can arise here if the extinguishing system concept (approved under building law) cannot be technically assessed by the expert(s). Of course, it can be certified that the building construction has been implemented. But is it also effective? There are statements from the highest building inspectorates that the expert does not have to question the concept, because if it has been approved, then it must be correct.

The author himself experienced a high-bay warehouse with a semi-stationary sprinkler system being approved in the area of a smaller volunteer fire department. The pump capacity of the fire department did not match the water requirement of the extinguishing system in the slightest. However, everything was approved (including the fire department's consent). The author refused to examine this project.

But even with very good extinguishing system concepts, in which a lot of thought has gone into the design, the test expert cannot say for sure whether the extinguishing system will be effective in the end.

Let's try it out

One way to give all those involved more security is to use certified protection concepts or to carry out project-related proofs of effectiveness.

With the guideline “VdS 3115 - VdS recognition of new protection concepts” (free of charge in the VdS webshop), VdS offers a procedure with which protection concepts can be evaluated. This procedure can be used to test concepts and evaluate deviations from the relevant regulations.

For example, various logistics providers have had extinguishing system concepts for their storage systems certified, as the relevant technical regulations themselves do not offer any concepts for their innovative solutions. In case of doubt, the solutions must be tested by means of proof of effectiveness (fire tests).[4] Once certified, the solution can then be used at various locations (taking into account all defined boundary parameters, of course). Of course, the certifying expert then also does not know whether the concept is effective. However, the reference to a certified protection concept will always have a high level of acceptance.

In addition to the certification of a concept, it is also possible to carry out project-related proof of effectiveness. These can be spray tests (without fire) to evaluate special situations or fire tests in various sizes.

[4] See also: Frank Ruland, „Schutzkonzept auf Basis einer Sprinkleranlage nach VdS CEA 4001“, s+s report 2/2020, S. 16 ff

At the end

We keep hearing that certain specifications should be made by the expert. He/she should say what you want. It must be clearly stated that an expert may not perform any planning tasks. If, for example, the fire protection concept requires an extinguishing system in accordance with FM Global specifications, the water supply must also be described. This is not regulated in the FM Global data sheets. And for systems according to DIN EN 12845, something must also be said about the quality of the components and qualification of the installers. The new version of the MVV TB mentioned above has further strengthened this position, as Annex 14 now explicitly states under 10.4.1: “All necessary information must be provided in the fire protection certificate.” Of course, it makes sense to involve the approving expert(s) in the concept development at an early stage, especially for larger projects, but the planning must be done by others.