Prior to dry-in of a building, constructing an outer frame within an external opening of the building by attaching a top piece to a top, attaching a first side piece to a first side, attaching a second side piece to a second side, and attaching a bottom piece to a bottom of the building opening. After constructing the outer frame within the external opening of the building, the method includes mounting glass to glass receiving surfaces of the top piece, the first side piece, the second side piece, and the bottom piece. After dry-in and interior wall finishing of the building, the method includes attaching a plurality of inner base caps to an interior of the outer frame. After dry-in and exterior wall finishing of the building, the method includes attaching a plurality of outer base caps to an exterior of the outer frame.