Liner tray wall systems are widely used for industrial and commercial buildings. Up until now, the main type used was the conventional solution with a thin (3 mm) separation strip between liner tray and outer shell. In the meantime, various solutions exist on the market to improve the thermal performance of this wall system. On the one hand, this paper deals with numerical studies that show how these new solutions reduce the heat transfer coefficient of liner tray wall systems. On the other hand, it is about the related increase in the fixing distance s1 and its influence on the mechanical performance of liner tray wall systems. Extensive experimental investigations have been performed on liner trays with a directly attached outer façade within the scope of the European RFCS Research Project GRISPE. Practicable calculation methods have been derived based on existing regulations and methods. This paper depicts by way of excerpts the results for liner trays with a directly attached outer façade for fastener distances that are not or insufficiently covered in the standards.