Therefore the theme of the roof-covering itself was a very important one. Now a copper-cap takes care about around 4000 eggs.

The architecture underneath should be reduced to nearly nothing. Therefore only two columns support the building and the stairway reinforces this construction.

There are no windows on the upper floor; natural light enters the exhibition room only from below through the outward-slanting glazing of the overhang superstructure.

The decision to cover it with copper finally based in a postulation of the building owner: Bertoni wanted to use the most long-lasting material for his house top. So we did. Finally the adjustment of the standing seams contrasts to the horizontal position of the roof. Its lower end is build by a compact framed copper rail.

In contrast to the glass, the lively structure of the material's patina highlights the importance of this building element. The special colour of the copper borrows the colours of the surrounding rooftops and positions the new building as an independent one, just as a fully integrated object in the neighbourhood.

An architecture critic, Anne Isopp, wrote about the museum:

(…) it recalls a jewellery box, not only because it is so compact, but also because it is precisely executed down to the smallest detail and yet serves merely as a showcase for the objects in the collection.

Another architecture critic, Iris Meder, finished her piece with the words:

(…) an obviously new building which seems to have been there forever.