The 4 July 2019 judgment in C-377/17 is an important reference point for understanding the evolution of the HOAI framework. This retrospective was prepared in November 2026.
The infringement judgment
The Court held that Germany had failed to comply with the Services Directive by maintaining mandatory tariffs for architects’ and engineers’ planning services. The ruling concerned the state’s obligations; the treatment of individual historic contracts requires a separate legal analysis.
Why the contract date matters
Do not apply a current HOAI summary indiscriminately to old appointments. Identify the date, fee agreement, applicable version and relevant subsequent case law. For current appointments, the text-form fee agreement under section 7 HOAI should be addressed clearly.
Four practical examples
Illustrative scenarios: the appropriate steps depend on the contract, evidence and applicable law. These are not reports of client matters.
A 2018 appointment
Establish the historical legal framework before calculating a claim.
A new appointment
Agree the fee basis in the required form.
A scope expansion
Record the additional services separately.
A disputed minimum fee
Avoid treating the 2019 judgment alone as a complete answer to a private contractual dispute.
Further guidance
Legal framework & further reading
Reviewed: 12 November 2026. Statutory references are to German law unless stated otherwise.