The design had two phases with fundamentally differing construction principles. The extreme length-width ratio demanded special construction considerations. In the first variant, the starting point was to develop a free floor plan with a load-bearing façade that would also function as a constructive stabilization. The façade was a continuous concrete shell in which the possible window openings were determined by the static restrictions this construction imposed. All the window openings had to be equipped with low spandrels. The fact that it was not possible to have façade openings stretching from the floor to the ceiling was particularly annoying, especially to Huub Smeets. He continued to advocate more transparency.

At the same time, in this first phase, the low-rise construction (the Colonnade) was still directly connected like a plinth to the high-rise building. In view of the desired layout variants in the five lower storeys, and the architecture-driven wish to link the Zonnewijzerplein at the foot of the Towre of the Vestdijk by means of a public passageway, a complex system of entrance and access was necessary. The decision to simplify this situation was reasonably obvious from an architectural standpoint, but it had great consequences for the office section. The Tower and the Colonnade had to be cut free of one another. Each section had to have its own entrance, and the three office layers in the Colonnade had to be divided from those in the lower storeys of the Tower. The problem of the passageway was also solved, and the offices in the Colonnade were assigned their own profile and address on the Vestdijk.

This rigorous solution was conceived, agreed and sanctioned in a consultation session with Ton van Daal and Huub Smeets in our office one afternoon. This is a typical example of interaction in which direct contact between the customer and the architect leas to a creative solution that none of the parties would have come up with on their own. In this particular case, it involved the programmatic claim on the one side and the wish to realize a continuous façade on the Zonnewijzerplein, on the other.

The principle of the enhanced openness of the façade necessitated a new construction principle, this time with a central concrete stabilizing core. In principle, the floors rest on a column grid in the façade. As a result, the triangular forms of the apartments (the 'half-diamond') could remain free of columns and the façade openings could be freely chosen. The grid of verticals (columns) and horizontals (floors) is directly recognizable in the façade structure. It has been treated differently in the west façade than in the east façade, in connection with the position of the desired balcony.

At the position of the loggia in the west façade, the columns are exposed. For this reason, they are round and, in conjunction with the shadow effect of the loggia's, they ensure an expressive west façade. On the east side, the columns are rectangular and, along with the floor edges that lie in the same plane, they form an orthogonal grid which is filled with glass displaying a wood print. This has replaced the wooden parts desired by Vesteda which could not be applied at such heights due to building-physical and material-technical reasons. Both façade structures fuse together with the glass curves and the floor edges at the north and south ends of the building. The massive concrete core places the building firmly on the ground on both long facades, and spans a crown over the building at the top, emphasizing its unity.