hollow glass block

glass block, glass brick

A hollow block of glass, usually translucent with textured faces; has relatively low thermal-insulation and low fire-resistance value; used in non-load-bearing walls.
References in periodicals archive ?
These are less energy efficient that standard hollow glass blocks and are very heavy to install.
In 1975, Ernest Friedrich at Rohm GmbH in Germany patented a gas-assist method for making one-piece hollow acrylic blocks to compete with hollow glass blocks used in construction.