As part of the EU project, INSYSME - INnovative SYStems for earthquake resistant Masonry Enclosures in reinforced concrete buildings - to optimise infill masonry the German project partners carried out an initial part of the project on flexural strength testing of high-tech clay block masonry in accordance with DIN EN 1052-2. In this a wide range of modern products was considered which at present is regulated in Germany by means of general building authority approvals. The test results show that the specifications for flexural tensile strength of high-tech clay block masonry in DIN EN 1996 are very conservative in most cases.