Practical considerations may impact panel thickness such as providing concrete cover and to accommodate aggregate sizes. If the panel requires no reinforcement, 3” thickness may be possible for cladding products although generally a 4” thickness is the practical minimum thickness for a cladding unit. Mild reinforced panels are more typically 5-6”. Other considerations include the span of the panel, incorporation of false joints, as well as lifting and connection devices. We highly recommended you consult a local PCI-certified precast producer for best panel design options, budget estimates, and project outcomes.