A panel insert is provided which is installed in a concrete wall form and secured at an intended location such that when the concrete is poured into the form and cured, the panel remains in place and through which holes or openings can be readily formed after the concrete wall has been constructed. The panel insert comprises a box or enclosure made of a suitable plastic or other material and having an interior filled with a structural and thermally insulative foam or other material. At least one gasketed flange is provided around the periphery of the enclosure which forms a watertight seal between the concrete and panel.