Planning bosses are expected to give the green light on Monday to changes to the scheme featuring 24 self-contained apartments on the corner of the square where it meets Winckley Street.
Original plans for a health club within the development have been scrapped because it was not felt it could be commercially viable and would not be able to offer enough facilities to compete with other clubs.
The health club would also be a noise nuisance to people living in the flats, it was felt. Additional parking will be added instead.
As part of the works, designed by the MCK Partnership, light wells will be added in to the basement. The existing annexe will be extended, while a five-storey extension will be added on to the back to provide basemenr parking on three levels and five two-storey apartments.

A council spokesman said: “The design is contemporary but sympathetic to the existing listed buildings.

The scale and form of the extension is in keeping with the existing buildings.”

The developers have also paid £20,000 towards environmental improvements in Winckley Square.

In recent years Winckley Square, a conservation area, has become a magnet for developers, seeking to attract young professionals back into the city centre.

Blackthorn is the third company to unveil plans to create luxuary apartments on the prestigious square, once the most desirable address in the city.

Developers Rowland Homes have acquired Grace House, a former girl’s school, to create around 40 upmarket apartments and penthouses.

Portergate Residential Developers, from Manchester, are to convert 22 Winckley Square, the former newspaper office into seven stylish flats.

The PR1 development is just one of a number of such projects to have sprung up in the area interspersed with listed buildings.