Before revision: History Cavity walls were first used in Greco-Roman buildings, but fell out of use until the 19h century, when it was reintroduced in the United Kingdom, gaining widespread use in the 1920s.
After revision: History Cavity walls were first used in Greco-Roman buildings, but fell out of use until the 19th century, when they were reintroduced in the United Kingdom, gaining widespread use in the 1920s.