A 23-storey tower will be built as part of a new four-building office complex in Birmingham city centre.

More details have now emerged about the next stage of the wholesale regeneration of a 4.1-acre site next to the Mailbox shopping mall which is currently occupied by the Axis building.

Phase one of the project, which was handed the green light in February, comprises a new nine-storey office building called One Axis Square, public space and the demolition of the existing Axis building.

Phase two, which was first revealed back in January, comprises three separate office buildings of varying sizes including the new tall tower.

Two Axis Square will reach up to five storeys and have two retail units on the ground floor.

Three Axis Square is the largest of the quartet of buildings planned for the site and will reach up to 23 storeys and overlook Suffolk Street Queensway with the potential for large shops and restaurants at lower levels.

Design sketch of the new Axis Square development
Design sketch of the new Axis Square development

Completing the scheme will be Four Axis Square which will be 14 storeys at its highest point and also contain retail units.

All of the new buildings will be arranged around a public square and a basement area beneath the complex will have space for 49 car parking spaces and 800 bikes as well as changing facilities for staff.

According to newly submitted planning documents, the entire project is expected to take about eight years to complete, would offer one million sq ft of commercial space and room for around 10,000 employees.

Detailed CGI of the first phase of the project, called One Axis Square
Detailed CGI of the first phase of the project, called One Axis Square

The project is being led by owner London and Continental Railways and both phases of the regeneration have been designed by London-based practice Fletcher Priest Architects.

LCR development manager Nick Clough said: "Since gaining detailed planning approval for One Axis Square, we have consulted on the wider plans for Axis Square to create a new, vibrant commercial office development in the heart of the city.

"We've received significant support for these plans, along with helpful feedback that has enabled us to make some refinements.

"I'm pleased to confirm that we have now submitted an outline planning application to Birmingham City Council."

More specific details and designs of the second phase buildings are due to be submited in a separate planning application in due course.