ISG has been appointed to fit out the 135,000 sq ft offices for financial firm Investec in the City of London.
The fit-out contract will see Investec move into four new floors at 30 Gresham Street, where it currently occupies two.
The project involves the full strip-out and fit-out of the existing floors, as well as the installation of an atrium staircase from levels four to eight.
According to ISG, 3D digital modelling has helped plan the logistical side of the project, including how to install the staircase within the building.
The office includes general open-plan workspace aimed at creating agile working environments, alongside internal meeting and video conference rooms and refreshment hubs.
ISG managing director of UK fit-out Matt Blowers said: “This latest win reflects the strength of ISG in the London office fit-out market.
“Demand for premium office space remains at a high level across London as organisations seek high-specification facilities in optimum locations.
“Investec is providing highly collaborative, modern working environments designed to attract and retain the best employees.”
The project is expected to complete in May 2018.