Area type

Census 2021 statistics are published for a number of different geographies. These can be large, for example the whole of England, or small, for example an output area (OA), the lowest level of geography for which statistics are produced.

For higher levels of geography, more detailed statistics can be produced. When a lower level of geography is used, such as output areas (which have a minimum of 100 persons), the statistics produced have less detail. This is to protect the confidentiality of people and ensure that individuals or their characteristics cannot be identified.

Lower tier local authorities

Lower tier local authorities provide a range of local services. There are 309 lower tier local authorities in England made up of 181 non-metropolitan districts, 59 unitary authorities, 36 metropolitan districts and 33 London boroughs (including City of London). In Wales there are 22 local authorities made up of 22 unitary authorities.

Coverage

Census 2021 statistics are published for the whole of England and Wales. However, you can choose to filter areas by:

• country - for example, Wales
• region - for example, London
• local authority - for example, Cornwall
• health area – for example, Clinical Commissioning Group
• statistical area - for example, MSOA or LSOA

Type of central heating in household

Central heating is a heating system used to heat multiple rooms in a building by circulating air or heated water through pipes to radiators or vents. Single or multiple fuel sources can fuel these systems.

Central heating systems that are unused or not working are still considered. No information is available for household spaces with no usual residents.

Occupancy rating for rooms

Whether a household's accommodation is overcrowded, ideally occupied or under-occupied. This is calculated by comparing the number of rooms the household requires to the number of available rooms.

The number of rooms the household requires uses a formula which states that:

* one-person households require three rooms comprised of two common rooms and one bedroom

* two-or-more person households require a minimum of two common rooms and a bedroom for each of the following:

1. married or cohabiting couple

2. single parent

3. person aged 16 years and over

4. pair of same-sex persons aged 10 to 15 years

5. person aged 10 to 15 years paired with a person under 10 years of the same sex

6. pair of children aged 10 years, regardless of their sex

7. person aged under 16 years who cannot share a bedroom with someone in 4, 5 or 6 above

An occupancy rating of:

* -1 or less implies that a household’s accommodation has fewer rooms than required (overcrowded)

* +1 or more implies that a household’s accommodation has more rooms than required (under-occupied)

* 0 suggests that a household’s accommodation has an ideal number of rooms

The number of rooms is taken from Valuation Office Agency (VOA) administrative data for the first time in 2021. The number of rooms is recorded at the address level, whilst the 2011 Census recorded the number of rooms at the household level. This means that for households that live in a shared dwelling, the available number of rooms are counted for the whole dwelling in VOA, and not each individual household.

VOA’s definition of a room does not include bathrooms, toilets, halls or landings, kitchens, conservatories or utility rooms. All other rooms, for example, living rooms, studies, bedrooms, separate dining rooms and rooms that can only be used for storage are included. Please note that the 2011 Census question included kitchens, conservatories and utility rooms while excluding rooms that can only be used for storage. To adjust for the definitional difference, the number of rooms required is deducted from the actual number of rooms it has available, and then 1 is added.

Age

A person’s age on Census Day, 21 March 2021 in England and Wales. Infants aged under 1 year are classified as 0 years of age.