There is interest in population statistics for the built-up areas in Scotland as they are generally more identifiable as the traditional towns and cities of Scotland than administrative areas such as Council areas, much of which consists of land that is not built up. The National Records of Scotland (NRS) uses information about postcodes (some 145,000 in Scotland) to define 'settlements' and 'localities' as good approximations to built-up areas.
NRS maintains data on unit postcodes, including a boundary enclosing all of the addresses assigned to the postcode. These postcode areas are used as 'building bricks' in the definition of settlements.
NRS produces Small Area Population Estimates at data zone level on an annual basis. These, together with information from the Royal Mail Postcode Address File, are used to classify unit postcodes as either ‘high density’ or ‘low density’. A postcode is defined as high density if it meets one or more of the following threshold conditions:
- The number of residential addresses per hectare exceeds 2.1
- The estimate of population per hectare exceeds 5
- The number of non-residential addresses per hectare exceeds 0.1
Once the postcodes are defined as high or low density, the population estimates in contiguous high density postcodes are joined together to form the built-up areas of Scotland. As boundaries to unit postcodes are subjective, a small amount of manual updates are required for rural areas to maintain ‘obvious’ high density boundaries. Where the population is 500 or more, the area is defined as a ‘settlement’.
Localities are intended to be more representative of the towns and cities in Scotland. Some settlements cover an extensive area, and consist of more than one distinct town or city. For example, the settlement of Glasgow consists of many towns, such as Paisley, as well as the city of Glasgow itself. So, some settlements are divided into constituent towns or cities (‘localities’). However, in most cases a settlement is exactly equivalent to the locality of the same name. Where settlements consist of two or more localities, the settlement is suffixed by the words 'Settlement of' in the tables.
It is recommended that users exercise caution when comparing the settlement or locality population estimates with previous years. Whilst an increase in population may be due to new build, it may also be due to the inclusion of existing housing which had previously been separated from the settlement by a low density postcode (and vice versa for a population decrease).
The sum of the settlement (or locality) population estimates will not add up to the total mid-year estimates for Scotland for the same year as populations outside settlements (or locality) are not included.
The population estimate for each settlement (or locality) is rounded to the nearest 10. For the small number of settlements (or localities) that cross local authority boundaries, the population estimate for each part is reported and also rounded to the nearest 10. The only exception to this is where a part of a settlement (or locality) has a population less than 15. In these cases, the population is added into the adjacent local authority which contains the main part of the settlement (or locality). As a result, the overall population figure for some of these settlements (or localities) may not exactly equal the sum of its parts.
For 2008, there are five new settlements. Buchlyvie, Cuminestown, Liff, Moniaive and St Fergus. No settlements have dropped below the 500 population mark. Due to areas of new developments, the settlements of Culloden and Glenochil Village have been enclosed in Inverness and Alloa respectively.