The Interior Ministry refurbishment proposal is based in a stagnant soundproof box. The acoustics plays a fundamental role in this project, not only concerning reverberation but it’s transmission as well. We proposed an inner uniform surface in order to create a buffer between the exterior spaces and the room. This thickness is composed by a set of cabinets and dense acoustic isolation which obstruct the adjacent spaces transmition. This interior skin definition is established on a foundation created by acoustic panels from the floor level until the door heights, creating a reference to a space structuring order. This vertical post element created from light colored wood is also responsible for the sound reverberation treatment.