Lodha is reporting £500m worth of sales in the last six months resulting in 85% of the residences now sold.
With just 44 apartments on offer, the building was formerly the US embassy, with notable ambassador Joseph P Kennedy, the father of JFK himself, a former resident.
It later became the Canadian High Commission from 1961 to 2014. Lodha UK, a subsidiary of India's Lodha Group, then purchased the building for a reported £310 million.
Situated on London's grandest square, and just around the corner from Bond Street and Mount Street, the historic building of No.1 Grosvenor Square has been reconstructed, brick by brick, for the 21st century.
With exceptional ceiling heights and grand balconies with sweeping views across London, No.1 Grosvenor Square is recognised as one of the world's most desirable addresses.
