A wall system for a building having a first room and a second room is provided. The wall system includes: (a) a first panel having a first batting material positioned between a first board and a second board; and (b) a second panel having a second batting material positioned between a third board and a fourth board. Further, at least one of the second board and the fourth board is formed from at least one mineral wool board. A building having a first floor, a foundation, and a first floor board area positioned between the first floor and the foundation is also provided. The first floor of the building includes a first room, a second room, and a wall system positioned between the first room and the second room.