“Box-type” CLT buildings are realized by connecting CLT panels through dowel-type fastener and mechanical anchor connections, which govern the lateral behaviour of these structures. However, while a lot of investigations in literature have been focused on the behaviour of connections placed at the base of CLT shear walls, typically hold downs and angle brackets, less studies have been focused on the behaviour of connections between perpendicular walls and how their affect the lateral response of CLT shear walls. This paper presents some results of a large experimental campaign aimed at investigating the effects of the interaction provided by perpendicular walls on the lateral behaviour of CLT shear walls. The findings of this experimental study showed that the structural interaction due to the presence of perpendicular wall significantly influence the lateral response of a CLT shear wall and increase its lateral performances, such as the lateral stiffness, the lateral capacity and the deformation capacity.