Interior construction structures and systems

A building construction system, comprising:

• a base building structure formed by a lower base building slab, an upper base building slab, and a plurality of base building wall slabs, the base building structure defining an interior therein;
• an interior building construction assembly positioned within the interior and comprising:
• a plurality of side walls, each of the plurality of side walls comprising a bottom end and a top end opposite the bottom end, and an exterior surface and an interior surface;
• a lateral support structure affixed to at least one of the interior surfaces of the plurality of side walls;
• and
• a finish ceiling configured to be suspended from the upper base building slab and positioned below the lateral support structure;
• wherein the bottom ends of the plurality of side walls connect to the lower base building slab,
• wherein a gap is defined between the exterior surfaces of the plurality of side walls and the plurality of base walls of the building, thereby decoupling the plurality of side walls from the plurality of base walls.