A spokesperson for Saga said it was in talks with the architect about a number of faults in the £20m building.
The spokesperson said: “Saga confirms that the buildings have been occupied for some six months, although there are a number of outstanding defects to be rectified. As there are still six months of the defects liability period remaining, the consultants and contractors are currently working towards a satisfactory resolution of these matters.”
Michael Hopkins and Partners declined to comment, and Saga’s spokesperson refused to give details of the problems. However, a project source said there were problems with the headquarters’ cladding system, which was designed to allow the building to be ventilated naturally.
The source said the building’s passive ventilation system allowed too much air to blow in, causing draughts and disturbances from rattling window blinds hitting the glazing.
The source added: “The fact that the building is also facing the Channel doesn’t help matters, but the bottom line is the system Hopkins designed isn’t working.
“The building is in one of the windiest parts of Britain, but the architect knew that at the start. The design was simply too ambitious for the location.”
Complaints have also been made about the ventilation at the Hopkins-designed £76m Inland Revenue headquarters in Nottingham, built in 1995. Staff said the natural ventilation system did not cool the building properly.