|Late Victorian Medium by Richard Russell-Lawrence|
A typical period house is an urban terraced or semi-detached house built over seventy years ago. The original front of the house usually still has distinctive features which are common to the period in which it was built such as a bay window. Bay windows began to be built after 1851 when both window and glass taxes were abolished. During the mid Victorian period (1851–1874) they were cant or straight sided.
The periods are not merely identified by the reigning monarch but by distinctive developments and features common to that generation. For example the reign of Queen Victoria spanned three generations and numerous developments which profoundly affected peoples homes such as the Public Health Acts of 1848 and 1875. During the late Georgian period (1774-1810) the population of the United Kingdom began to change from having an urban minority of twenty-five per cent. By 1914 the country had an urban majority of eighty per cent.