Skanska has won a £73m contract from developer Helical to refurbish 207 Old Street in London.
The building – also known as the Tower – is part of the Bower development on the edge of the City.
Skanska’s project will bring more than 15,000 sq m of offices and 650 sq m of retail space to the tech business area known as Silicon Roundabout.
Works will include stripping back the building to its original frame; adding three new floors; extending the floor plates by about 15 per cent; installing two lifts; and recladding.
The scheme is targeting an Excellent rating through sustainability initiative BREEAM.
Skanska managing director Steve Holbrook said: “It’s great to be working with Helical on another scheme.
“At Old Street, we’ll be able to showcase our wider expertise in sustainable refurbishment work and mixed-use developments, helping to redefine the building and create a modern workplace in this thriving part of London.”
Work is expected to be complete by June 2018.