As the principal contractor for the first phase, McGee will deliver the complex engineering project to overhaul and extend 30 South Colonnade for developer Quadrant and its joint-venture partner Oaktree Capital Management.

30 Colonnade and the renamed YY London building

McGee has been on site since last May carrying out the soft-strip and demolition works.

The latest deal will cover enabling and structural strengthening works to the 1980’s steel frame building.

Complex demolition work includes the removal of two storeys from the 62m tall building, above the 11th floor slab while keeping the existing floor slab intact.

The project will see then see the frame extended upwards with three new floors and then re-building the building from the ground up.

Seb Fossey, group managing director, said: “As specialists in London, we understand the scope, risks and constraints associated with the scheme which means we engineer the best possible method to deliver the works.

“Our operating model ensures that when procured early, we’re able to collaborate with key stakeholders, mitigate risk and save programme time in doing so.”