Technical Assessment

DIBt's national technical approvals, general construction technique permits, ETAs, evaluations, project-related approvals, project-related construction technique permits and the structural design type approvals contribute to a high level of safety in construction, while opening up new markets for innovative construction products and design solutions.

DIBt’s decisions are prepared by the Institute’s three technical departments: 

• Department I – Structural Engineering
• Department II – Health and Environmental Protection, Registration of Energy Performance Certificates
• Department III – Building Physics, Technical Building Equipment

A look into DIBt’s assessment activities highlights both cross-cutting and discipline-specific challenges. Overall, DIBt's activities reflect the key themes driving the construction industry. Furthermore, a clear link between technical assessment, technical regulation and building research is evident throughout DIBt’s work. Here are some key topics from the years 2023 and 2024.

Carbon footprint and concrete: How ‘green’ can concrete be?

Reducing the carbon footprint remains a key issue for the construction sector. Engineers and researchers across all disciplines – from concrete, masonry, glass, wood and metal to plastics and composite construction – are exploring new solutions. They have two main starting points: the materials used and the design.

Concrete presents an important lever to reduce carbon emissions from construction, particularly due to mass effect. As part of new product development, manufacturers are replacing CO₂-intensive cement clinker with alternative binders. For example, granulated blast-furnace slag and limestone are increasingly being used as substitutes. In October 2024, DIBt issued the first decision for a binder with a high share of finely ground recycled concrete. 

The application of geopolymer concrete is somewhat more complex. The reason: this concrete does not contain cement clinker as a binder. Instead, the binder is formed by an inorganic structure of aluminium and other water-soluble silicates. DIBt approved a geopolymer binder as early as 2019. In 2024, DIBt approved concrete components for sewage pipes based on this geopolymer binder. The geopolymer binder was also used to construct a building in Schleswig-Holstein on the basis of a project-related approval and construction technique permit.

The carbon fibre reinforcement meshes, first approved by DIBt in August 2024, offer new structural possibilities. Due to the low concrete cover required, concrete components reinforced with carbon fibre mesh can be more resource-efficient. 

Innovations in timber construction include innovative hybrid wood-wood beams, i.e. beams where different types of wood are combined to achieve a higher-performance solution. In 2023, DIBt granted approval for such a beam for the first time. Strong laminated veneer lumber lamellae are arranged in the tension and/or compression areas. Solid timber is used in cross-sectional areas that are subject to lower stress. As part of a research project, an FEM model was developed to analyse the beam’s load-bearing capacity by modelling its cross-section using the finite element method.

In multi-storey timber construction, structural integrity and fire safety are closely interlinked and must be considered together, given timber's inherent combustibility. 

In September 2024, the Conference of Construction Ministers endorsed the revised Model Guideline for Timber Construction. The federal states thus prepared the ground for an extended application of timber components also where special fire protection requirements apply. Following the adoption of the guideline, the project team responsible for the Model Timber Construction Guideline within the Conference of Construction Ministers, which is convened by DIBt, successfully prepared the introduction of the amended Model Guideline with version MVV TB 2025/1.

Modular construction holds appeal for its potential to reduce building times, lower costs and allow for easier dismantling and repurposing. However, standardisable research on the fire performance and smoke resistance of certain modules is still lacking. Meeting these requirements is vital, in every sense of the word, especially for permanent installations, such as multi-storey residential buildings, offices, and especially critical environments like hospitals and retirement homes. At the beginning of 2024, the DIBt's 'Modular Construction' project team published principles for the verification of fire-resistant components in modular steel construction. These were elaborated further at the end of the year by adding test setups (publication in 2025). The principles provide orientation to DIBt customers when submitting applications or providing test reports and verification. It is expected that more general construction technique permits will be granted in 2025. 

Incorporating renewable energy sources into the built environment brings its own challenges. DIBt issues decisions for a wide variety of mounting systems for photovoltaic modules. A current trend consists in embedding the modules in the roof cladding or façade so that the modules become an integral part of the roof and façade. With this in mind, DIBt’s ‘Fire Behaviour of Construction Products’ expert group is working on a cost-effective test programme to determine the fire performance of rear-ventilated PV modules as part of the facade.

With MVV TB 2023/1, the Technical Building Rules have also been adapted to account for the increased use of large-format PV modules in construction. For PV modules in the roof area with a mechanically fixed glass surface, verification of fitness for use (with regard to mechanical strength) is only required for individual pane sizes larger 3.0 m².

Renewable fuels are one way of reducing our dependence on fossil fuels. At present, paraffinic fuels and fuels from synthesis or hydrogenation processes are increasingly entering the market. 

The abbreviations ‘XtL’ (where ‘X’ is a variable for the energy source, e.g. GtL for (bio)gas, BtL for biomass or CtL for coal, and ‘tL’ stands for "to Liquid") and ‘HVO’ (hydrotreated vegetable oils) are commonly used for these fuels, depending on the production process. 

The composition of these new paraffinic fuels has an impact on existing storage tanks for substances hazardous to water or hydrocarbon-limiting systems for wastewater with biodiesel, biofuel oil and ethanol contents, such as those used at petrol stations. Both tanks and hydrocarbon-limiting systems are approved by DIBt.

Plastic storage tanks experience material swelling when exposed to fossil fuels, altering the tank’s wall properties. This change can lead to compatibility issues when switching to alternative media, such as paraffinic fuels. Plastic storage tanks specifically approved for paraffinic fuels have been available since mid-2023. Switching between fossil and paraffinic fuels has so far been ruled out in DIBt decisions. However, research in this area is still ongoing.

The situation is less problematic for steel storage tanks, where a media change is generally possible under certain conditions.

The effects of paraffinic fuels also need to be taken into account for wastewater treatment plants used in petrol stations. Based on the available findings and analyses of the properties and effects of the new fuels, DIBt is currently working on the future requirements related to material resistance, but also design, operation and maintenance of wastewater treatment plants.

Both the amended Construction Products Regulation (CPR) and the amended Energy Performance of Buildings Directive (EPBD) contain requirements for future Life Cycle Assessment (LCA) of construction products and buildings. It is not yet clear whether these changes will also affect the Model Building Code.

Since 1968, DIBt has been the German approval body for innovative construction products and construction techniques. DIBt approval procedures comprehensively assess innovative building materials and design solutions against the applicable regulations in terms of stability, fire safety, environmental and health protection, sustainability, safety in use, sound insulation and thermal insulation.

In 2023 and 2024, DIBt granted

Products with a European Technical Assessment – better known by its abbreviation ETA – can be CE-marked and marketed across Europe. DIBt is a leading Technical Assessment Body in Europe, both in terms of ETAs issued and European Assessment Documents (EADs) developed.

In 2023/2024, DIBt issued

DIBt is also actively involved in the European Organisation for Technical Assessment (EOTA), the technical organisation that manages the ETA route throughout Europe. Numerous DIBt officers are involved in the various EOTA working groups, contributing actively to the organisation's work. DIBt Vice-President Karsten Kathage and Matthias Springborn, Head of the EOTA Section at DIBt, are members of the EOTA Executive Board, with Mr Springborn also acting as chair of the EOTA Technical Board since April 2021. The revision of the Construction Products Regulation was – and remains – the central topic of his term in office.

The core of EOTA is and remains the technical work on European Assessment Documents. Significant milestones have been achieved, in particular, in fixings and reinforcement. DIBt has contributed to these achievements as convenor of the Fixings Expert Group and in many cases also as responsible Technical Assessment Body. Here are some examples of additions to EADs for which DIBt has issued the first ETAs in 2024.

• EAD 330499-02-0604 – Bonded fasteners can now be qualified in terms of fire resistance.
• EAD 330499-02-0604 and EAD 330232-01-0601-v05 – The EAD has been reworked to include the behaviour of bonded and metal fasteners in steel fibre reinforced concrete.
• EAD 330232-01-0601-v02 – This variant allows for mechanical fasteners to be assessed for a service life of 100 years and considers stiffness characteristics.
• EAD 330008-04-0601-v01 – The variant allows anchor channels to be verified for fatigue shear behaviour.
• EAD 160129-01-0301 – The EAD for couplers for mechanical splices now includes the load-bearing capacity of grouted couplers.
• EAD 160202-00-0301 – This new EAD features assessment methods for assessing stud connectors for anchoring in reinforced concrete members as well as for connecting steel members with reinforced concrete members.

It is not always obvious whether a CE-marked construction product is fit for use in a specific context in Germany. Verification gaps occur when assessment methods for specific product characteristics needed to assess whether the final component or structure will comply with the Building Codes are missing from harmonised European standards (hEN). Examples include the bonding behaviour of safety glass, which has a direct impact on the residual load-bearing capacity of glazing after breakage. Residual load-bearing capacity is required in Germany for overhead glazing, for example, to prevent people standing under the glazing from being injured by falling glass fragments. Furthermore, shortcomings in the harmonised standards regarding health protection or concrete repair products have long been documented and criticised by the German authorities. DIBt evaluations provide a voluntary tool for manufacturers interested in comprehensive verification.

The revised Construction Products Regulation is poised to address many of these shortcomings directly at European level and give member states a greater say in harmonised standardisation.

In 2023 and 2024, DIBt issued

DIBt has been issuing project-related approvals and project-related construction technique permits for Berlin since 2018. This allows customised product and design solutions to be safely implemented. DIBt is closely involved in the construction industry in Berlin through the issuing of project-related approvals/project-related construction technique permits and is witness to the city's constant transformation.

In 2023 and 2024, DIBt granted

Some insights into this area of work.

The advantages of a DIBt-approved structural design type can be summarised as follows: once reviewed, the design type can be used throughout Germany as often as you wish. Structural design type approvals are particularly useful when the same design is to be used in different locations. This avoids the need for multiple reviews, saving time and cost. DIBt's structural design control authority can draw on the expertise of over 100 highly qualified engineers. The review is carried out in accordance with the Technical Building Rules using state-of-the-art soft- and hardware.

In 2023 and 2024, DIBt granted