ECJ to decide on new HQ ECB?

The European Central Bank is planning to construct its new premises on the former GroƟmarkthalle (pictured above) site in Frankfurt am Main, Germany. It is now temporarily based in Frankfurt's Eurotower. As is well known, the location of European Central Bank was fixed by the Amsterdam Treaty along with other major institutions.

However, the descendants of the original architect of the GroƟmarkthalle have brought legal proceedings before Frankfurt’s district court to prevent the market being rebuilt in the way the architect of the new HQ intends, claiming breach of copyright on the original layout of the building.
Forbes now reports that the district court has suspended this case until the ECJ decides whether the district Court or the ECJ itself is competent.