Plans to "sensitively refurbish" the London Hilton on Park Lane in what will be the hotel's first major makeover since opening in 1963 have been approved by Westminster City Council.
The reconfiguration of the property, which involves expanding the size of guest bedrooms, is expected to take the property from 453 bedrooms to between 350 to 448 bedrooms.
The hotel was the first Hilton to open in the UK and with 28 storeys (now 31) was once London's highest building. It is still one of the 50 tallest structures in the capital. Property tycoons brothers Richard and Ian Livingstone, who bought the hotel in 2001, plan to "refresh" the building to "reduce visual impact".
Plans submitted by Hopkins Architects show the hotel will be updating its façade and excavating an additional three basement levels to allow for a larger subterranean ballroom, meeting rooms, leisure facilities, a casino and basement car and cycle parking.
The hotel's rear ballroom podium will be partially demolished and a new four-storey building will be developed to provide up to 29 serviced apartments. The hotel will also create 28 flats on the top eight floors of the building, offering views over Hyde Park, which are expected to sell for around £7m each.
A spokesperson for Hilton Worldwide said: "Throughout the hotel's history there has been a continuous investment programme and we are pleased to have received a resolution to grant consent for the next phase of this flagship London property. There is still further work to do to conclude the discussions and agreements with Westminster Council but this is an important milestone as we seek to further enhance this international hotel."
Latest video from The Caterer