Members’ Forum 2026 – Infopage

HDD categorisation

In the current edition of the DCA guideline, Chapter 10 divides HDD projects into two categories depending on their complexity, i.e. their degree of difficulty. This classification can be used to determine the scope of the required engineering and preparation works as well as the corresponding responsibilities. The aim of this classification is to ensure that the scope of this project preparation is proportionate to the effort involved in the construction work and is therefore practicable.

During the DCA Annual Congress 2025 in Bamberg, this categorisation was already one of several topics discussed at the workshop on Thursday afternoon. The contributions showed that there is a need for further discussion on this topic. Among other things, the following questions will be addressed with the participants of the members’ forum:

• Is the number of two categories (standard and complex) adequate?
• Are the classification limits for these criteria appropriate?
• Should exceeding one limit already lead to classification in the ‘complex’ category?
• Are the responsibilities correctly defined?
• Is such a classification generally practical and compliant with other applicable regulations?

Within the framework of this members’ forum, we would like to continue the discussions that have been started and lay the basis for further revision of this chapter of the DCA guideline as part of the next revision.

DCA Technical Guideline – Chapter 10