The pre-wall system can be used in the construction of buildings, with multiple advantages in terms of production time and environmental impact. This type of walls is formed by two thin precast concrete panels, linked with steel trusses to create a hollow precast wall module, which are assembled at construction site, adding reinforcement in critical regions, namely, in connections, and casting concrete into the core. Recently, the durability and sustainability of this wall system were enhanced, using a high-durability concrete only in the cover and for the core was used a concrete that combines low cement dosage with lightweight aggregates. This paper presents a study, with both experimental and numerical components, developed to characterize the behaviour of corner connections between two perpendicular pre-walls. The connections between perpendicular pre-walls are must more complex than traditional connections made in situ because the space to define the reinforcement detailing is very limited, making difficult to assure a proper transmission of the internal stresses between the two walls. Different amounts of reinforcement, concretes mixtures and reinforcement detailing were tested. Nine numerical simulations were also performed to further enrich the results discussion. Cracks pattern, deformation, strength and stiffness were analysed. Conclusions are drawn and guidelines are proposed to design this type of connections between pre-walls.