Externally the decorations were simple: travertine in the lower part and large bricks realized in plaster in the rest of the building. A remain of this plaster decoration is still visible today in the facade, below the roof.
The interior of the senate house was very different. The walls were covered with the most valuable variety of exotic marbles as the splendid floor.
Luckily the flloor dating to the ancient times survived throughout the centuries and it's still visible today.
The building changed function in the middle ages to become a church, the original decoration were kept and not spoiled.