An East Anglian building technique that used large, unfired, clay bricks set in a clay mortar. The bricks were made of local clays mixed with chopped straw, shaped using a simple wooden mould and air-dried. The sizes could vary from about 22 x 12 x 5 inches to 18 x 6 x 6 inches. The wall surfaces were originally finished with a clay plaster, which was often tarred for weatherproofing and then sanded to take a colour-wash, but by the 1920s cement rendering was the most frequent surface treatment. In some cases the clay lumps were hidden behind a brick facing. A brick or stone plinth was usual to give the blocks a dry foundation.