A pre-cast panel has forms mounted thereon for forming post-like flanges and a footing. Upon erection of an array of panels, the flanges and footing may all be cast on-site, with appropriate reinforcing/coupling means present within the form core volumes, by filling such forms with binder material such as concrete. Optionally, an upper beam may also be formed in a similar manner, the pre-cast panel being provided with an upper beam form which is attached to the wall portion of the panel and interconnected to the previously described forms.