Floor and ceiling panels and methods of constructing a floor system for a building are described. In some embodiments, a panel includes a plurality of joists, a corrugated form deck disposed above and attached to the plurality of joists, a ceiling substrate disposed below and attached to the plurality of joists, and an in-floor radiant heat member disposed between the corrugated form deck and the ceiling substrate. In some embodiments, the panel includes a plurality of joists, a corrugated form deck disposed above and attached to the plurality of joists, and a sound dampener disposed between the corrugated form deck and the plurality of joists. In some embodiments, the method includes attaching a pre-assembled panel to a frame of the building and pouring concrete onto the panel so that a radiant heat member is separated from the concrete by a corrugated form deck of the panel.