A Suffolk school has been left disappointed after Ofsted inspectors said it had “serious weaknesses” despite marked improvements to its exam results this year.

Alde Valley School in Leiston was created last year following the county council’s decision to move from a three to two-tiered educational system in the Suffolk Coastal area.

Ian Flintoff, headteacher at the school in Seaward Avenue, said: “We are of course extremely disappointed with the Inspection judgement of Serious Weakness centered around the progress of some groups within the school.

“We accept the judgement and the leaders of the school have been working in a very determined way to address the key issues, all of which were already identified priorities for us in our development plan.

“The inspection team highlighted that we are a fast improving school and in 2013 our GCSE results rose by 10% and our A/level results were amongst the best in Suffolk and a record for the school with 81% of students achieving all of their grades at C and above.

“This was against a backdrop of huge challenges during the county council reorganisation of schools in our area and our own rebranding of the school to reflect the change to two-tier schooling.”

The school is currently going through the process of becoming an academy with the sponsorship of New Academies Trust (Suffolk New College) and the conversion should take place on February 1, 2014.

Mr Flintoff said: “I have confidence that as a sponsored academy within the next two years, we will have made the progress to take us to “Good” in all Ofsted judgements and will have a clear strategic focus for improvement.”

Principal of Suffolk New College, Professor Dave Muller said: ‘We are very pleased to be sponsoring Alde Valley as it converts to academy status.

“The Ofsted outcome provides a useful baseline for us to move on from and I am confident working alongside the senior team that the school will improve.

“The college is committed to providing opportunities for the young people of Leiston and the surrounding area.”