motto: a building acting as its logo The dominating topic of the concept of the designed building is the principle of analogy with an elegant stone fixed in between the street plane and the surrounding buildings levitating at the same time. This ´gemstone´ is rough, uncut – only at those places touching the surrounding buildings it is finely faceted to fit in; we can say it is sharply cleaved to let light deep in. The shaping of the new building at the same time carries an imprint of the previous form – by its shape taken in, the façade to Národní třída is vertically divided into two parts (although still one building) referring to the two buildings formerly standing at this site. The volumetry of the top parts works with the principle of stories stepping back – although not in the strictly classical sense of the meaning. The building’s mass in the form of a broken crystal does not distinguish the exact line between the vertical façade and the roof – it behaves as a homogeneous unit faceted at those points where bonds to surrounding buildings need it. The surface is natural – scarred by irregular slots of windows. The building will start shining at dusk. Thousands of diode LED lights will illuminate the entire translucent glass surface (from behind of window reveals); moreover, these lights are able continuously and very slowly – even unnoticeably – change the light colour. The building can change in time – it is emerald green at one moment and amethyst purple in half an hour. Each side of this fragile surface is clad in a stone veneer including oblique roof parts and the soffit above the streetscape. The second essential and inseparable part of the concept is what happens below the stone. Not only the gemstone is unique, but its setting, too. It is a broken, yet in fact a homogeneous space – an artificial dream landscape vertically oscillating between the first basement and the ground floor (and up to the 1st floor). A pair of depressions dominates this landscape where the vestibule to the congress areas is located at one of their bottoms and a swimming pool as the focal point of the wellness/fitness zone in the other. The entire landscape is walkable – only some areas are so steep that they do not allow walking; comfortable staircases are provided elsewhere. The internal courtyard cut into the stone block is left open; glazing starts at the ceiling level above the ground floor. The top floors of the old and the new building are not connected – connection only exists on the ground floor and in the basement. The reinforced concrete cast in-situ frame with mostly a loadbearing envelope is wrapped in a skin consisting of opaque, translucent glass elements (scales, tiles, shingles) whose tiny size allows to cover even a relatively rather complex mass. There is an air gap left between the loadbearing structure and the façade with lights on at night. The building lives a different life by day and at night. The clear glass envelope connects the ground floor very tightly to the streetscape. To separate the interior environments, we close the depression with a swimming pool on the ground floor by a frameless glazed wall so that the required effect of a maximally open unobstructed space would not be disturbed.