RADVA Corporation began the development of a structural panel utilizing expanded polystyrene and galvanized steel profiles bonded into a unitized panel by a heat activated adhesive in 1975. The panels were initially used for residential construction in the USA and a few years later, in Mexico. In 1985, RADVA sold substantially all of its rights to Atlantic Richfield (ARCO) and subsequently repurchased these rights in December 1987.

The operations were extended via joint ventures or license agreements into Mexico, Australia, Russia, South Africa, Poland, Guam, Philippines, and Turkey. In May of 1998, RADVA sold 95% interest with all intellectual rights in the Thermastructure Building System to ThermaSteel Corporation. ThermaSteel Corporation is associated with the World Housing Technology Center located in Izmir, Turkey.

ThermaSteel Corporation is a leading innovator of "Build Green" Structural Insulated Panels; using steel and Expanded Polystyrene (100% Recyclable). The panels have been produced since 1976 under various trademarks such as RADVA Panel, Thermastructure Panel, Wallframe, and Insulsteel. The main headquarters and manufacturing facility is in Radford, Virginia. Other manufacturing facilities exist around the globe. Panels have been used throughout the USA and in 27 other countries.