Prefabricated building panels combine new and unexpected element dimensions and materials with the effect of reducing overall weight and depth while simultaneously improving panel performance such as thermal insulation. As compared to former panels, prefabricated building panels according to exemplary embodiments of the invention generally include thinner concrete slabs, wider separations between concrete and support framing, and new material choices for anchors connecting slabs with framing. Exemplary panels are compliant with energy codes such as the latest ASHRAE and IECC.