Abstract: A structural panel having a structural inner core with a male member and a female member. The female member is configured to receive the male member of a vertically adjacent panel therein and has a locking slot. The structural panel also includes a locking member operatively engageable to the male member and configurable between an unlocked configuration where it does not substantially project outside of lateral wall surfaces of the male member and a locked configuration where it projects outside of at least one of the lateral wall surfaces of the male member and is engaged in the locking slot of the vertically adjacent panel. A panel assembly, a method for building a building wall using multiple structural panels, a corner securement assembly for at least two horizontally adjacent structural panels and a method for securing two horizontally adjacent panels in a corner configuration are also provided.