Abstract: A flip core door assembly comprises an outer frame structure, inner panel and a plurality of flexible strips. The outer frame structure includes an upper frame member, a lower frame member, and a pair of opposing frame members. The inner panel includes a front side, a rear side, an upper side member, a lower side member and a pair of opposing side members. The inner panel is adaptable to place in an open space of the outer frame structure. The plurality of flexible strips is attached to the upper side member, the lower side member and the pair of opposing side members. The plurality of flexible strips is adaptable to secure the inner panel air tightly with the outer frame structure which allows a user to easily remove the inner panel thereby flipping the inner panel within the outer frame structure.