Local authorities are responsible for ensuring sufficient school places for pupils, including accurately forecasting demand. The Department collects forecasts of future demand for pupil places from each local authority, covering the next five years, through the annual school capacity survey (SCAP). Local authorities do not distinguish the gender of pupils within this data.
The latest published SCAP data, relating to the position as reported at May 2015, can be found at:
https://www.gov.uk/government/publications/school-capacity-academic-year-2014-to-2015. Local authority level data for pupil forecasts can be found in tables A5 for primary and A6 for secondary. This data covers the periods 2015 to 2019 for primary and 2015 to 2021 for secondary.