The Custom House has two storeys and a hipped roof laid with rectangular slates. The building's plinth and the outside steps are also clad with slates. Use of the best materials was during the reconstruction era reserved for the community's most used buildings and areas such as private business and public buildings, the town park and the market square. This lead to careful detailing of entrances, foyers and public meeting places using slate, marble and various kinds of hard wood. In the case of the Custom House the chosen such material was slate.