ABSTRACT
Population lies at the heart of projections of future contexts of the demand for the built environment. A reasonably accurate picture of the scale and structure of population in the recent past can be built up from survey and census data. For example, the 1981 Census of Population indicated a population in Great Britain of about 54.7 million people [1]. This was officially projected to rise to 56.4 million by 2001 [1], now revised down to 56.1 million [2]. The size and demographical structure of population depends on births and deaths, and inward and outward migration. The main difficulty in projecting population at the national level tends to lie in projecting rates of birth. Over the last hundred years crude birth rates per 1000 population have varied between 13 and 35 [3]. Projected birth rates can have a large effect on population projections-in 1964 the Registrars General were projecting a population in 2004 of 72 million [3]. Reasonable assumptions of possible variations in the factors to be considered gave
boundary figures of 56 and 85 million [3]: it is the lower boundary figure which is closest to current projections. (Death rates are far less volatile than birth rates).
