Methodology

School capacity

Published

Introduction

This methodology provides information on the data sources used in the ‘School capacity’ release. It also provides information on the data quality and coverage and highlights any key limitations.

Data collection

Information in the ‘School capacity’ release has been derived from 3 data sources: 

  1. School Capacity survey – an annual survey returned by local authorities that collects information on the below areas. Further detail is available at School capacity survey 2021: guidance for local authorities.
  • Primary and secondary school capacity
  • School sixth form capacity, collected as a voluntary field
  • Pupil forecasts, including forecasts of the number of places to be funded through housing developer contribution (HDC) agreements and Housing Infrastructure Fund (HIFs)
  • Local authority planned places, including additional, bulge and removed places

2. School Census – a termly census of all schools in England, used to provide pupil number on roll figures.

3. Central Programmes data – administrative data about the provision of places through centrally funded programmes. Further detail is available in the 2021 technical guidance for the school place planning estimates accompanying the ‘School capacity’ release.

Changes to School Capacity survey in 2021

Local authority forecasts now include places which are funded through HIF, they are also collected/reported as a separate field.

Local authorities were provided with additional tools to support forecasting: a core projection model from Office for National Statistics and GP registration data at postcode level.

Data coverage and quality

All the data submitted by local authorities in the School Capacity survey have undergone a thorough data cleaning process with validation at source and at the department. Anomalies have been raised with local authorities to check that the guidance has been followed. Except where noted in the tables, all data has been signed off by local authority’ Directors of Children’s Services (or equivalent roles) as complete and accurate.

School capacity

School capacity includes community, foundation, voluntary and middle schools as deemed. It includes academies, free schools and sixth form places. 

School capacity excludes special schools and nursery places.

In constructing the timeseries of school capacity data, data for 2019/20 is not available due to the cancellation of the 2020 school capacity survey due to Covid-19 (which means the 20/21 net change in school places since the previous survey, is not comparable to previous years, because this change is over two years rather than one year), and minor revisions have been made to 2016/17 and earlier data to account for slight inconsistencies in methodology in how the published tables were produced. 

In the 2009/10 published tables, school capacity data for academies were originally published separately from local authority maintained schools. In this release, 2009/10 school capacity data for academies and local authority maintained schools have been combined together to be consistent with subsequent years' releases.

2009/10 national, regional and local authority aggregations exclude 13 secondary academies where no school capacity figure was provided. They are included in the school-level underlying data. 

School sixth form capacity

Sixth form capacity in schools was also collected separately for the third time in the 2021 School Capacity survey, as a voluntary field. It includes sixth form capacity in community, foundation, voluntary and middle schools as deemed. It includes sixth form capacity in academies/free schools. It excludes special schools.

These statistics are no longer considered experimental as coverage is now at an acceptable level. Any comparisons between 2017/18, 2018/19 and 2020/21 should still be treated with caution as changes from year to year may not reflect actual changes in figures but may simply indicate improvements in data quality. They are, however, useful to assess capacity in sixth forms attached to schools and have been published for transparency purposes. 

83% of local authorities with at least one school with sixth form pupils on roll submitted complete data in 2021 compared to 65% in 2018. Regarding the local authorities with incomplete data, there are a small number of schools where the sixth form pupils on roll may include pupils from separate providers, therefore the local authority is unable to report any corresponding capacity for the school in SCAP. 

Local authority pupil forecasts

Forecast data is generated by local authorities based on their own data and local knowledge. These forecasts are challenged extensively during data cleaning processes. There are variations in the forecasting methodologies and data sources used across local authorities. This means there is the potential for local anomalies within the methodology. As with any forecast figures, there will be variation between the forecasts and the subsequent actual pupil numbers.

Uncertainty is even greater in the 2021 forecasts due to various issues with forecast model input data, such as: potentially understating actual pupil numbers in 2020 and 2021 as a result of children not being on roll for various reasons during the pandemic; increased uncertainty in future external migration patterns as a result of Britain’s exit from the EU, travel patterns during and following the pandemic, and potential influxes from things like the UK’s visa offer to British Overseas Nationals in Hong Kong; changes to historic internal migration patterns as relocation patterns change; and increased uncertainty around housing development completion times due to supply chain issues and labour resources (again as a result of Britain’s exit from the EU as well as the pandemic).

As with all forecasts, the level of accuracy is expected to reduce as forecasts are made further into the future. Care should be taken when using forecasts from the later years.  

Forecasting accuracy measures are calculated and published for each local authority in the Local Authority School Place Scorecards. The Local Authority School Place Scorecards can be found here: https://www.gov.uk/government/collections/school-places-scorecards

Forecasting accuracy is derived retrospectively, once actual pupil numbers for the forecast data become available. Most local authorities’ forecasting accuracy tends to be within +/-1% one year ahead. 

Local authority planned places

Local authority planned places, including additional, bulge and places to remove, are based on local authority estimates. They include only places for projects where the local authority has a high degree of certainty the project will go ahead. Further information is available at: School capacity survey 2021: guidance for local authorities

Estimates of future school place demand (place planning)

The ‘School place planning estimates’ data file includes the estimated number of places needed in order to meet future demand.

These estimates factor in existing capacity reported at 1 May 2021, additional capacity from local authorities planned places, and additional capacity being provided through centrally funded programmes (e.g. free schools). This capacity is then compared with the forecasts provided by the local authorities. This comparison of capacity and pupil forecasts is made at planning area level (see ‘Definitions) and national curriculum year group level, i.e. places have to be available in the correct planning area and year group. Further information on how these estimates are calculated, how to interpret them and their limitations are available in the 2021 technical guidance accompanying the ‘School capacity’ release (see supporting files under ‘Explore data and files’) .

Relationship with 'National Pupil Projections' publication

The aggregated national pupil forecast figures in the ‘School capacity’ release will differ to the National Pupil Projections published annually by the Department for Education due to methodological and timing reasons. 

Local authorities supply the department with their own low-level planning area forecasts using their own methodologies that are based on a variety of local factors (including ONS data on live births, local migration patterns, pupil yield from housing developments and data provided by local health bodies). These are then added together to create the national figures shown in the ‘School capacity’ release. 

National Pupil Projections are calculated at national level only and are based on ONS age-based projections, adjusted for school years; they also use historic population and birth data from ONS and the department’s school census figures.

The pupil forecasts within the ‘School capacity: Academic year 2020/21’ release are comparable to ‘National-level pupil projections: July 2021 (2020 update)’ which was updated on 22 July 2021. They are based on the mid-2019 population projections from ONS and cover a longer time period (up to 2030) than in the school capacity release. They provide national pupil forecasts by actual age whereas this publication provides local authority forecasts by national curriculum year group. Differences in the methodologies used by individual local authorities for pupil number forecasts mean that the aggregated totals in the school capacity release will differ from the national-level projections, but the trends in both are broadly similar.

Although the trends are similar, the number of pupils is projected to peak one year earlier in SCAP than in the national pupil projections. This difference is partly due to methodological differences mentioned above, and partly because there is an element of double counting in the SCAP forecasts when aggregated. This is because forecasts are provided by local authorities for the highest predicted point within the academic year. There will always be more demand when these forecasts are aggregated to a national level, compared to national pupil projection.  Pupils move between local authorities throughout the academic year so could be double counted in the forecasts. Whereas national pupil projections are based on the number of pupils in schools in January, by age as at the previous 31st August, therefore should not be affected by this. 

Definitions

Capacity 

The number of places the school can provide for. For maintained schools (local authority funded), capacity is defined by a physical measurement, and calculated in the net capacity assessment. Academies are not required to complete a net capacity assessment. Therefore, their final net capacity is reported as per their funding agreement (subject to any information that the local authority holds in addition).

For capacity, schools are reported as deemed. Therefore, for a middle-deemed primary school all capacity is counted as primary and for a middle-deemed secondary or all-through school all capacity is counted as secondary. Sixth form places are included in the total secondary capacity. 

Free schools are reported at their final intended capacity and in their final intended planning area. The capacities of local authority maintained schools are reported as built and ready-to-use.

Local authority planned places

Additional places - permanent places that will not move through the school with a specific cohort.

Bulge places - temporary places used to accommodate large cohorts. They move through the school as the cohort progresses.

Removed places - places local authorities plan to permanently remove from their school capacity.

Number on roll

Number on roll is the number of sole registered and dual main registered pupils attending a school as reported via the school census. 

Number on roll (actual pupil numbers) within the ‘Local authority pupil forecasts and forecast housing developer contribution (HDC) places’ data file are based on the January 2021 census. Number on roll figures within the ‘School capacity’ and the ‘School sixth form capacity data file' are taken from the May census for the relevant academic year, except for new schools (including schools that have become academies) where figures are based on data gathered during the School Capacity survey. Number on roll relates to pupils in reception year group and above.

Planning areas

Planning areas are groups of schools, often (but not exclusively) in a similar geographic area, reflecting patterns of provision. The planning areas for primary are different to the planning areas for secondary. Schools may be assigned both a primary and a secondary planning area if they have pupils on roll in both primary and secondary year groups. This includes all-through schools, middle-deemed primary schools, and middle-deemed secondary schools.

Pupil forecasts 

Pupil forecast data is split by phase, so primary includes year groups Reception - 6 only, and secondary includes year groups 7 - 14.

Schools at or over capacity

A school is identified as at or in excess of capacity when their number on roll is greater than or equal to capacity.

Unfilled places

The number of unfilled places is the extent of capacity above number on roll. A school is identified as having unfilled places if the capacity is higher than the number of pupils on roll.