Contractor Kajima has brought in a fresh project team to work on the £30m PFI extension to the Sheffield Northern General Hospital after delays to the project, it emerged this week.

The firm refused to comment on the nature of the problem but it is thought to be 19 weeks behind schedule on a build programme that has been running for 34 weeks. The difficulties are being caused by piling and foundation work.

The contractor brought in the team in July. They are working with two members of the original team, including the project manager Chris Olley. Kajima said it had assured Sheffield Teaching Hospitals Foundation Trust that the scheme would be open on time but conceded that delays had occurred.

A Kajima spokesperson said: “While delays have set in, largely due to setbacks with foundation work, we expect the project to be completed on time especially with the new team on the job.”

The spokesperson added that the previous group had been depleted by “natural wastage” when people had left the project.

The ward block, known as the Hadfield wing, will replace Victorian wards. Sheffield Teaching Hospitals NHS Foundation Trust aims to have the wards in full operation by next autumn.

The scheme, designed by architect Sheppard Robson, will have 168 beds and be used to treat elderly patients.