Planning for schools in established areas


Case Studies

The Client

Willoughby Public School Parents and Citizens Association


Community concern that growth pressures at the school had been underestimated.


.id provided independent verification of official State projections using SAFi forecasts.


Confirmed that the school had reached peak demand. This changed the community's view of the problem and opened the way for constructive solutions to be discussed.

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The community around Willoughby Public School in Sydney were concerned that the NSW Department of Education were underestimating population pressures the school faced. They sought out .id for an independent assessment and help in understanding the forecasting process. Ultimately, .id found that the Department of Education’s projections were reasonable, allowing the community and department to work together to tackle over-crowding concerns in the present day, including the potential requirement for an additional school in the local area.


Willoughby Public School Parents and Citizens Association (WPSPCA) recently contacted .id regarding mounting concerns of the growth pressure being felt at Willoughby Primary School (WPS). WPS believe that the school is overcrowded (with over 1,000 students) and this is only set to worsen based on anecdotal evidence in the community regarding population growth.

In particular, WPS had questions regarding the validity of the Department of Education NSW projected student numbers within their catchment and were seeking an independent assessment as to the validity of the forecasts.

WPSPCA had been accessing population forecasts for Willoughby Council. However, the geographic granularity and detail of the data was not enough to meet their needs. They also required some assistance in interpreting the numbers.

The .id Solution

.id’s consulting team agreed to take on this work pro-bono and provide an independent view as whether we felt the Department of Education’s projections for growth in student numbers at WPS were realistic based on our forecast population growth in the area.

To do this, .id accessed its small area forecasts (SAFi) which are micro geography based forecasts designed to be built up into specific catchment areas, including school catchments. SAFi forecasts are also produced by single year of age which allows organisations to plan for specific age based services.

Using SAFi and .id’s spatial analysis application (Placemaker), .id were able to work with WPSPCA to define the schools catchment area and provide an assessment of the total demand for primary school education (i.e. 5-11 year olds) within the catchment going forward.


What .id found was that the number of primary school age children (persons aged 5-11 years) is forecast to increase modestly over time. In 2011, there were estimated to be 1,887 5-11 year olds in the catchment. By 2021 this figure is estimated to be 2,133 (representing an average annual growth of 25 children or 1.2% pa). According to .id’s SAFi forecasts this rate of growth is forecast to slow further over the medium to longer term with an additional 15 primary school age children forecast to be added into the catchment annually in the five years to 2026 and a further 3 per annum in the five years from 2026 to 2031 (this represents an average annual growth rate of 0.7% and 0.1% respectively).

.id’s assessment of these figures was that the school age population within the catchment is ageing and the growth pressure that has been felt on the school will slow as the primary school age population ages and moves into secondary school. That being said, there is still forecast to be a critical mass of primary school age children, yet the levels of growth are forecast to subdue.

Of course, in this case, .id’s analysis only considered total demand. When planning for schools and school enrolments however, the Department of Education need to take into account a number of other factors and make assumptions, such as:

  • Yield rates – the proportion of 5 year olds who attend school (versus pre-school).
  • Market share – the proportion of total students who attend a public/private/Catholic school and how this share is forecast to change over time.
  • Competitor landscape – the relative attractiveness of one school over another may mean in some cases students will travel further than their closest school to attend a school deemed to have a better reputation. In the case of WPS however, enrolments are restricted to those students who live within the designated catchment area.
Although in this case, .id only provided an assessment of total demand within the catchment, .id’s rate of growth forecast among the primary school age population was found to be lower than that forecast by the Department of Education. Based on this simplistic assessment .id concluded that the enrolment forecasts for WPS appeared reasonable and adequate.

This assessment provided WPS with the evidence base required to feel comfort in the enrolment numbers forecast by the Department of Education. The question for WPS and the wider community now becomes one of whether the school itself is suffering from overcrowding (i.e. too many students) and if there may be a requirement for an additional school site in the local area in order to reduce class sizes.

Learn more about .id’s services for education providers.

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