This means that architects and engineers are generally entitled to subsequent payment if the agreed flat-rate fees with clients with whom they concluded an architect or engineer contract before 1 January 2021 (so-called old contracts) were below the minimum rates of the HOAI in the version up to 31 December 2020.
In the case to be decided by the BGH, the owner of an engineering firm had asserted a claim for remuneration in the amount of approx. 100,000 euros in court, whereby he subsequently calculated the amount in accordance with the HOAI (2013). Originally, a flat fee of approx. 55,000 euros had been agreed. The Court of Appeal was of the opinion that the plaintiff was entitled to the remuneration because the contractually agreed lump sum price violated the minimum price character of the HOAI as mandatory price law. However, the BGH dismissed the opposing party's appeal as unfounded.
After answering its questions in the preliminary ruling procedure, the VII Civil Senate has now decided that the provisions of the HOAI, which regulate the binding price law, are to be applied without prejudice to the ECJ ruling from 2019 (see above loc. cit.) and in the specific case led to a claim by the engineer for additional payment.
In view of the above, it should be noted that an architect or engineer can in principle demand a minimum fee in old cases if the flat-rate fees agreed with clients were below the minimum rates applicable at the time.
