The MAS was designed as a sixty-meter high tower. Every storey of the tower has been rotated a quarter turn, creating a gigantic spiral staircase. This spiral space, in which a facade of corrugated glass is inserted, forms a public city gallery. A route of escalators leads the visitors from the square up to the top of the tower.
Façades, floors, walls and ceilings of the tower are entirely covered with large panels of hand-cut red Indian sandstone, evoking the image of a monumental stone sculpture. The four-colour variation of the natural stone panels has been distributed over the façade on the basis of a computer-generated pattern. The spiral gallery is finished with a gigantic curtain of corrugated glass. Its play of light and shadow, of transparency and translucency turns this corrugated glass façade into a light counterweight to the heavy stone sculpture.
The museum square at the base of the tower is an integral part of the design. The square has been designed in the same red natural stone as the tower and is surrounded by pavilions and terraces as an urban area for events and open-air exhibits. The central part of the square is sunken and forms a framework for the large mosaic by artist Luc Tuymans.