In June, pupils from the school won a UK-wide award for their film-making abilities.
Park School’s principal Bernie Davis, though, said that the growth in numbers had brought “significant challenges”.
“This increase is a testament to the strong confidence in the teaching, care, and outcomes delivered by the school,” she said.
“However, class sizes are now at or beyond recommended limits.
“Specialist space such as changing rooms and shower facilities have been repurposed as classrooms, and staff rooms are increasingly used for teaching, reducing essential space for staff wellbeing and collaboration.
“The rise in pupil numbers has also placed considerable pressure on staffing, workload and resources.”
She said the funding had “not consistently kept pace with this growth”.
“The strain is beginning to impact the quality of provision and pupil wellbeing, as space, time and adult support become increasingly stretched,” she said.