Block, block of flats or square called in an urban area and a built-up area, which is enclosed by the paths and roads, or topographical conditions (eg railway line, river) and consists of several directly adjoining land or parcels and their outer block edges. The building block represents a typical urban design dar. It is formed by multi-storey apartment buildings, residential and commercial buildings or townhouses in closed design. This design is also called the perimeter block.
The block development is a typical urban design. This design has been used in the medieval European city centers of the Hanseatic cities. Similarly, we find the design in baroque inner city areas, such as the Dutch Quarter in Potsdam. Most typically it is for the absolutist Urban Development and the Mietskasernenviertel during the founding period incurred after 1870 the major German cities. In response to the housing shortage of the 1920s built housing co- residential blocks with large courtyards and social small apartments. At the same time these urban planners but also for alternatives to the then widely prevalent perimeter block and found this in the line construction, that is, in the parallel arrangement of several rows of houses. The advantage of this construction, which in Germany was widespread especially during the period of reconstruction in the 1950s and 1960s, was mainly seen in the uniform tanning of all dwellings and better ventilation of the area.
During blocks during the Middle Ages by the usually unplanned sequence of adjacent buildings arose, they were already in antiquity (examples Miletus and the model Roman city that follow a checkerboard pattern ), intensified since the Baroque period of city planners " on the drawing board " designed as geometric bulk form and then parceled out for development.
Building blocks also form the basis of spatial structure for the collection of statistical data on the population structure. The visualization of 3D city models, one often works with simplified solids, which should correspond to the real building blocks.