A Croydon High School which became an academy to have more control over improvements has received a worse grading from Ofsted than before the change.

Shirley High School, on Shirley Church Road, received an overall rating of requiring improvement from the education watchdog earlier this month after an inspection on November 14 and 15.

This was the first full Ofsted inspection of Shirley High School since it move from foundation to academy status on January 1 in 2012 after the school’s governing body voted unanimously on the change.

Before becoming an academy, the education watchdog had given the school an overall rating of good, saying its students left ‘as confident, mature and likeable young people’.

The school’s website outlines its reasons for becoming an academy, stating: "This decision has been made because the school wishes to take advantage of the benefits associated with academy status.

"These include increased control over how the school is run, direct funding, the ability to control and prioritise how the money is spent, the ability to make its own decisions about proposals for improvement, increased freedom in the curriculum and potential to innovate."

However, the report published on December 6 indicates that the achievement of pupils and the quality of teaching are in need of improvement.

The report states the quality of teaching does not lead to consistently good progress for some students, assessment by teachers is ‘inconsistent’ and the teaching of literacy across the curriculum is ‘not strong enough’.

It also calls for an improvement to the school’s 6th form, with students taking AS level courses achieving below average and those taking A levels not always making rapid enough progress.

Leadership and management are in need of improvement too, according to OFSTED, with inspectors citing actions not always being planned "with sufficient urgency" and checks of the quality of teaching not always being accurate.

Nigel Barrow, the school’s headmaster, said: "The recent inspection, which was conducted under a new, more rigorous, inspection framework, identified some aspects of the school that now require attention.

"We welcome this opportunity to further improve our school and will be implementing the recommended changes as a matter of priority."

Mr Barrow also acknowledged that the AS curriculum for the Sixth Form’s first year was not "best suited" to some learners.

However, the report did commend the behaviour of students at the school, due to above average attendance, a low number of exclusions and behaviour in lessons being ‘positive’.

Inspectors also highlighted good progress from students in performing arts and sixth form vocational subjects, who talked with enthusiasm about the teaching they receive.

Mr Barrow said: "There is much positive in the report and it is good to have confirmation that our students behave well; feel safe; enjoy their learning; are well supported in lessons and that our broad and balanced curriculum is still recognised as a strength of the school."

Mr Barrow added that there are now "clear plans" for the further improvement and that the school expects to set a new school record for both GCE and GCSE passes in 2014.

An overall grading of requiring improvement means the school will receive another inspection within the next two years.