The new residential housing in the microdistrict consisted almost exclusively of five-story prefabricated concrete block apartment buildings popularly known as "khrushchyovkas". Three nine-story high-rise apartment buildings were built in 1969, and several more were constructed later, as well as seven brick-built twelve-storeys. The apartment buildings were meant primarily to accommodate industrial workers who came to Vilnius from other regions of the Lithuanian SSR and from other Soviet Republics. They typify the Brutalist architecture of the era. The principles governing the design of the microdistrict were set forth in books by the University of Moscow planners, for instance in "New Element of Populating. En Route to the New City" published in the USSR in 1966 (although the concept of the "new element" has been dated to 1959); the book was later published as "The Ideal Communist City" in the United States, United Kingdom and Italy. According to the book, the optimal apartment size was about 600 square feet (56 square metres), with one bathroom and two bedrooms. Single-family homes were considered "too