The triangular form, very uncomfortable for construction, caused the dimensional design, brightly worked out by the author. The Senate’ size is close to the Arsenal. Both constructions are made level in height. The building is shaped as a triangle with an inner yard, divided with additional blocks into three parts: the central pentahedral and two side trihedral ones. In the middle of the main façade there is an arched passage leading to the inner yard. This passage is fashioned like a triumphal arch with a four-column ionic portico and a fronton. Inside the majestic rotund, topped with a gigantic green cupola, the Yekaterininskiy (Catherine’s) hall is located. All the Senate’s buildings are connected with a hallway along the yard’s perimeter.

The façades are designed in austere style of early classicism. The Round Hall of the Senate belongs to architectural masterpieces. Contemporaries used to call it “the Russian Pantheon”. The Hall’s diameter is 24,7 m; its height is 27 m. It is adorned along the perimeter by a Corinthian colonnade and covered with a vault that has 24 windows at the base. Sculptural thematic bas-reliefs adorn interfenestrations.

The Senate’s construction was a new stage in forming the type of a large public building. Hereinafter, it was taken as a model of a public building in many Russian towns.

In Soviet times, the Senate housed the country’s Government. In 1992-1995, the building was reconstructed for the residence of the President of the Russian Federation. Historical interiors have been preserved only in the Round and Oval Halls, the last one’s design is not less exquisite. The Representative’s offices of the residence are decorated in the XIXth century interior style.