Abstract: A prefabricated, custom-built shower pan with a drain hole for use in a shower stall is provided. The shower pan comprises: (a) an acrylic-based solid surface upper layer; (b) a polystyrene foam layer; and (c) a planar base layer with raised edges, the base layer being durable, rigid and relatively lightweight. The polystyrene foam layer is framed by the base layer and covered by the acrylic-based solid surface upper layer. Also provided is a shower pan comprising: (a) an acrylic-based solid surface upper layer; (b) a base layer comprising a planar base with raised edges, and a system of stringers; and (c) a waterdam. The stringers are substantially straight, horizontal wooden supports which collectively incline toward the drain hole. They are relatively evenly distributed within and adhered to the rectangular-shaped base. Each stringer has an incline on its upper surface, and one end abutting one edge of the base.