Google has paid £730 million ($1 billion) for the central London offices it has been renting in a fresh commitment to the capital and getting workers back to the office.
The purchase of the Central St Giles site near Tottenham Court Road will provide space for 10,000 employees - around 3,500 more than Google currently employs across the country.
The tech giant plans to spend millions refurbishing the site to incorporate outdoor working areas, hybrid working meeting rooms and flexible working spaces that "foster innovation, creativity and inclusivity."
Senior Vice President Ruth Porat said: "We have been privileged to operate in the UK for nearly 20 years, and our purchase of the Central St Giles development reflects our continued commitment to the country’s growth and success."
Chancellor Rishi Sunak welcomed the purchase as "a big vote of confidence in the UK as a world-leading tech hub" and London Mayor Sadiq Khan said the investment "will help London maintain its position as a world leading technology hub."
The purchase of the Central St Giles office is being made alongside a new development being built for the company in King’s Cross.
Last year the firm developed a Work Location Tool for its US employees, which meant some staff with long commutes who opted to work from home permanently had their pay cut.
Google said it expects fewer than 30,000 of its almost 140,000-strong global workforce to work remotely following the pandemic.