Somerset Geographies

In order to analyse data for an area we often use various administrative or statistical geographic boundary to divide the county up.  This page aims to introduce some of the more commonly used boundaries, where they come from and what they represent.

You can view interactive maps of the County, Electoral Divisions, Parishes and Built-up Areas on our Boundary Map page

Somerset: Our work generally covers the administrative area of Somerset as serviced by Somerset Council.  The ceremonial area of Somerset also includes the areas administered by the unitary authorities of North Somerset and Bath and North East Somerset.  Other neighbouring authorities include Wiltshire, Dorset and Devon.

Electoral Divisions: These are the areas represented by members elected to Somerset Council. There are currently 55 Electoral Divisions, with each Division represented by 2 councillors. Somerset Council adopted the Electoral Divisions which previously formed Somerset County Council when it was formed as the unitary authority on 1st April 2023.

Parishes: Somerset is divided into 329 civil parishes, which originally arose from Church of England boundaries. They range from the very small (communities of around 50 people) to the very large (for example, the whole of Bridgwater). 

Lower Super Output Areas (LSOA) and Middle Super Output Areas (MSOA): Parish, Electoral Ward, District and County boundaries change over time. In 2001 following the Census, the Office for National Statistics (ONS) created its own boundary system so areas could be compared consistently over time. The smallest geographic areas are known as Output Areas (OA). OAs fit into Lower Super Output Areas (LSOA), which in turn fit into larger geographic areas Middle Layer Super Output Areas (MSOA). In 2001 throughout the UK each of the LSOAs contained around 1,500 people and the MSOAs around 7,500 people.  Following the 2011 Census, LSOAs and MSOAs were revised to take account of population changes.  In Somerset this resulted in some LSOAs being split into 2 and others being merged together, the overall number of LSOAs did not change however and MSOA were untouched.  In Somerset, there are 327 LSOAs and 71 MSOAs.

Built-up Areas (BUA): As part of the 2011 Census ONS created the Built-up Area geography similar to the previously named rural areas.  The definition follows a “bricks and mortar” approach, with BUAs defined as land with a minimum area of 20 hectares (200,000 square metres), while settlements within 200 metres of each other are linked.  This point about settlements within 200 meters being linked can result in towns & villages that local people would describe as being separate, being combined.  The best example in Somerset is the Burnham-on-Sea BUA which includes Highbridge, Berrow and Brean.

A number of census tables have been released with figures based on these BUAs.  These figures are produced by aggregating Output Areas that are at least partially covered by the BUA area.

Postcodes: The postcode system introduced by the Royal Mail uses boundaries which are not aligned with those used by administrative areas or the ONS. Consequently, where data are available only at postcode level they can be aggregated to any other geographical boundaries, where appropriate.