International architecture firm Kohn Pedersen Fox (KPF) has several projects underway, such as One Hudson Yards and a new master plan for New York City’s Port Authority. Most recently, in a reinvention of spaces, KPF has submitted plans to build 11 floors on top of Richard Seifert’s 1972 30-story King’s Reach Tower, which has been renamed South Bank Tower. Located on London’s South Bank, the tower will be transformed into a mixed-use building consisting of 191 high-rise luxury apartments.

KPF and collaborating engineering firm Adams Kara Taylor (AKT II) have applied to Southwark Council to raise the tower an additional 144 feet. The offices no longer meet modern day requirements and have remained vacant for about six years. An extensive overhaul proposal to transform the building into a mixed-use space – including creation of retail space, pool and gym on the ground floor, and various extensions – was approved in October 2011, so the firm already has authorization to add six floors. In seeking approval for five additional floors, KPF wants to take the 364-foot structure to 508 feet, which will extend the tower by more than a third of its original height and will offer space for 36 additional residential units.

The extended tower would become part of a new group of tall buildings on the southern bank of the River Thames, which includes the recently completed Shard by Renzo Piano and the impending One Blackfriars by Ian Simpson Architects.

Extending South Bank Tower by a third is a world first, according to an AKT II project engineer. KPF has become a frontrunner in skyscraper development, but despite the fact that the tower is a different approach than the firm’s customary sky-high towers, sustainability remains a focal point of the plans.