AbstractA correct design project should not only control the load‐bearing capacity and stability of the individual elements but also ensure proper cooperation between these elements. Connection of masonry walls is crucial for durability of the building, safety of its users, and thermal insulation of external walls. The design and construction process is successful only if loads can be transferred properly between the particular structural elements. The issue of joints between the walls and consequent transferring of vertical and horizontal loads between them is still not sufficiently recognized. Very few tests have been performed on this issue, while operating standards require that the designer ensures proper cooperation between intersecting walls. In this paper, information is collected on the code requirements, design procedures, producer's recommendations as well as the laboratory tests results, and conclusions in the topic of joints in masonry walls. Additionally, results of preliminary tests performed by the authors on the joints of autoclaved aerated concrete (AAC) masonry walls are presented.