Since the opening of the EU domestic market, foreign investors and companies are looking to do business in Germany. Also, foreign clients are interested in finding out on which system German architects' and engineers' fees are base. The fifth edition of the bilingual (German and English) printed version of the "HOAI" (Official Scale of Fees for Services by Architects and Engineers) has been revised and updated according the 7th amendment from 10 July, 2013.