As a compact cuboid measuring 40 x 46 x 24 meters and clad entirely in white limestone, the building is perfectly synchronized with its surroundings. A solid stone shell with a delicate, preciously treated surface is broken up by modular openings in the facade and roof.
A 10-meter wide outdoor stairway leads from the entrance level to 3.40 meters above the courtyard level. Inside, a 250-square-meter glass-covered atrium forms the central axis for the exhibition halls situated around it. The atrium is 19 meters high and links the three upper levels. A lower atrium connected to the upper atrium through an opening in the ceiling is 9 meters high and connects the two lower exhibition levels.
From the entrance level, the main stairway on the long side leads over the mezzanine with the shop and café to the two upper levels and the two lower levels. Another subterranean level is used for storage and utilities. Two representative, two-story-high rooms are directly adjacent to the atrium.
Childcare and educational facilities are situated in the bridge to the old building. The auditorium with its separate outside entrance is under the outdoor staircase.
The administrative offices are in the adjacent old building wing, which can be reached over the bridge. Delivery zones and workshops are in the Oval Wing and are connected to the new building through an underground tunnel.
On each floor, four large exhibition halls are positioned following a modular layout and are separated from each other by a common access core. Each hall is subdivided with partition walls depending on the respective exhibition concept. Daylight enters the four upper levels from the side or from above through equally sized window openings. In addition, three halls are illuminated through elongated windows along the upper edges of the walls. An artificial lighting system provides for even lighting of the exhibition walls. The lowest level of the museum, which has no daylight illumination, is used for special exhibition purposes. The halls are equipped with a special light ceiling.
White limestone (Vratsa) for the facade, roof, walls, ceilings, and floors in all visitor areas and the access cores; oak parquet flooring in the exhibition halls; patinated brass for all visible metal parts.