The application of that robot system for the automatic assembly of commercial cavity blocks is the subject of the following report. The entirely different characteristics and abilities of assembly robots are not taken into consideration. However, their dimensional tolerance is relatively small (0.5 mm). Furthermore as cavity bricks, they have conic and oval recesses. Both features are strongly favourable for automation. This report will highlight specific problems during automized construction assembly with commercial standard assembly elements, and help to solve them.