The design rationale for the award-winning GPO and Postal Headquarters building was one of ?simplicity?, with the interplay of horizontal planes, solid, and voids. The basic external materials consist of glass mosaic tiles, with geometrical aluminium panels to blend with the modern Islamic architectural identity of the adjacent Dayabumi complex.

The building not only solves the technological and functional problems encountered in a Post-Office headquarters but also the design constraints placed on it by virtue of its location in the Dayabumi complex.