T: Reinforced AAC panels in the UK have been used in past, but these tended to be acting as roof units and to a limited extent fl oor units, with walling elements occasionally used horizontally as fi re walls or thinner vertical elements for partitions. In more recent times, their use in housing has been explored as a series of vertical storey height, solid wall elements (each element being 600 mm wide) to form the outer fabric of construction. In this form of construction a thickness of 200 mm will act as the main load-bearing component of the structure as well as making a signifi cant contribution to the overall thermal performance of the building. The vertical load resistance can be determined using the European Standard EN 12602. However, little data existed in the UK to enable the design of the walls to resist horizontal lateral load and resistance to racking. This paper reports on some preliminary tests to determine the vertical and horizontal spanning capacity of walls made with large elements. These tests were on storey height walls or 1 m high walls each 2.4 m long for the determination of their vertical and horizontal spanning capacity respectively. The walls were built off a slip plane to ensure as little friction at the base as possible, loads were applied using air bags. The racking tests followed the principles of EN 594 which applies to timber structures. The modes of failure in the fl exural tests were as expected although the results were quite variable. In the racking tests localised failure occurred at the point of applying the racking load in half of the tests although the results were not so low as to be discounted. Further tests are needed to establish the variability to be expected and to eliminate the localised failure in the racking tests.