Betta Bilda was made by Airfix in the 1960s and 70s
Plastic bricks with stud and socket connection between rows, very similar to Lego, but with thin roof tiles connecting together by a stud and hole arrangement.
Bricks came in red or white in various lengths but always one stud wide. Special wall parts include angled gable bricks, curved bricks and arches.
Various designs of windows and doors including opening garage door. Later sets also had larger special window, door and wall sections in yellow or blue.
Roof tiles were usually green, but red ones also exist. They include plain full and half tiles, ridge tiles, internal and external angle tiles and ridges and tiles incorporating a flat studded section for a chimney.
A castle accessory set offered such parts as curved bricks for towers, half arches, a gate with drawbridge, arrow slits and peaked wall coping.
Betta Bilda also offered wheels and axle blocks to make vehicles but generally stuck to architectural parts.