In order to be able to evaluate the architectural and engineering services as precisely as possible, the HOAI divides them into so-called service phases.
The fees for the individual service profiles, such as buildings or interiors, are specified in the HOAI's fee tables as "from-to" values, which corresponds to the minimum and maximum values.
However, the HOAI is not binding, but only serves as a guideline for the remuneration of architects and engineers.