Unlike the buildings that make them, cities are living, growing, and changing organisms. The needs and desires of a given urban populace can shift with the economy, technology, and culture. But as a population evolves, the buildings that make up our cities stay static. This incongruency often results in new construction to fulfill new needs, or demolition to clean up outdated infrastructure.

Note

This article originally appeared in the spring 2023 issue of KPF Review. Watch the accompanying video here.

Sometimes, however, when a particular mix of conditions is met, building conversion becomes the optimal, or even inevitable, architectural approach to urban upkeep. As we’ve demonstrated with many projects around the world, when a building has certain functional structural elements but hasn’t kept up with the times, conversion can be an environmentally friendly approach for dramatically transforming a site and its surroundings. With thoughtful, strategic design interventions, our conversions can create necessary programmatic updates, optimize the public realm, and maximize sustainability through embodied carbon and other efficiencies. As a firm with a philosophy of long-term commitment to the buildings and neighborhoods we impact, conversion projects represent one of the key architectural tools we employ for maintaining the functionality and beauty of our cities.

Southbank Tower

London, UK

Sited along the Thames and overlooking Blackfriar, the 1970s era South Bank Tower was built to enjoy a vibrant locality, enviable views, and attractive amenities such as a private art gallery and roof terrace. Originally designed by Richard Seifert as a part of a larger master plan for the area, the 30-floor tower was conceived as an office building with retail at its base. At the time, it was state-of-the-art. The 70s-style offices housed a publishing company’s headquarters, and the tall design with its vertical fins was futuristic enough for Southbank to feature as a disguised spaceship in the popular British comic book 2000 AD.

Southbank Tower, before and after, viewed from the Thames River. Credit: Timothy Soar.

Ironically, by the actual year 2000 AD, the tower was outdated. Its thick, brownish fins were tired looking and, both from an interior and exterior perspective, didn’t align with modern aesthetic standards for outward views and an open, light, glassy look. Due to site renovations and changes to the surrounding urban fabric, Southbank had developed unclear access points, poor security and maintenance, and several critically underused spaces, such as its rooftop terraces. In addition to material needs, the programmatic demands of downtown London had evolved—companies required open offices, residents wanted to live in city centers, and shoppers were drawn to immersive, street-centric retail experiences.

The existing office floorplate (right) and the new residential floor plan.

With an excellent structure, iconic history, and plenty of room for improvement, Southbank Tower represented an ideal candidate for a conversion. KPF was brought in to lead the redesign of the tower. After analysis, several architectural interventions were proposed to optimize the tower for the new century.

First, to address the programmatic needs, the original floors of the tower along with 11 newly built floors to be stacked on top were designated for residential use. This meant surgically reimagining how the interior walls and circulation of the building could be resituated to create contemporary high-end apartments. The podium and lower levels of the tower remained office space but were also reimagined to be open floor plans, making them attractive to modern technology and service work tenants.

To unite its isolated elements and solve its access and circulation issues, an atrium and series of passageways were strategically placed to connect the tower and the branches of its podium. The waterfront section of the site was also rethought, and the rooftop spaces on the podium were reconnected to the offices and residences they now serve. Combined with aesthetic improvements throughout, the conversion created a sense of place for South Bank Tower, resulting in immediate tenancy and several design awards.

Credit: Timothy Soar.
The Southbank Tower terraces allow residents to enjoy views over London, or find a landscaped escape. Credit: Timothy Soar.

Landmark Central

Hong Kong, China

Strategically converting a singular building can create an identity for the site itself. Strategically converting a series of interconnected buildings across a downtown can create an entire neighborhood where one hardly existed before. For Hong Kong’s Central district, KPF took on the challenge of converting and connecting several towers and podiums to transform the area from an office- and vehicle-heavy space to a vibrant destination for luxury retail and hospitality.

In the early 2000s, this was a bold and untested pursuit. The common thinking at the time was that office towers and luxury destinations should be kept separate—you shouldn’t stack Park Avenue atop Fifth Avenue.

Grischa Ruschendorf

However, Hong Kong, like the rest of China, was in a state of rapid change, and the 1960s office buildings in its downtown were quickly becoming outdated. KPF’s unprecedented decade-long commitment to transforming the neighborhood has driven the manifold increase in real estate value of an area that was, before intervention, quickly slumping into derelict office space.

At the time, retail space needed improvement. The existing shops were arranged in large, one- or two-story interior atria, leaving the street bare. At the Landmark mall, we transformed the interior into a stepped, three-story space, and around the neighborhood, we reclad street facing façades to bring retail to the urban realm.

Diagram of the Connect 12 project, a series of pedestrian paths through Hong Kong’s Central district.

We also spearheaded the Connect 12 project, a series of elevated bridges creating a second level of pedestrianized public space, floating above the street and linking interior retail throughout Central. Taken together with the reinvigorated retail, experiencing Central became immersive and pedestrian-oriented, with stores and public space woven through several buildings and the street. As a result, Central has become one of the premier luxury retail destinations in Asia, attracting the highest end brands and hosting fashion week events, positioning itself on the global roster alongside Tokyo, Paris, or New York.

Complementing the retail, KPF also redesigned the 1960s era Prince’s building, at the time an outdated office, into The Landmark Mandarin Oriental. By retaining the structure of the historic building but rethinking its circulation and interiors from front door to back, the tower was successfully transformed into a hotel aligned with the needs of Central’s new global, high-end clientele.

Exteriors of Landmark, including the Mandarin Oriental hotel (left) and the storefront of Louis Vuitton (right). Credit: H.G. Esch.

Oriente Green Campus

Lisbon, Portugal

Our success with converting Central was due in large part to our philosophy of committing to built spaces beyond the timeline of a single project, opting instead to think about the resilience and success of our projects in years and decades to come. With this ideology, our work gravitates toward projects in urban spaces that are experiencing meaningful change and growth—places where architectural problem solving can contribute to crafting dynamic, healthy cities. Thus, when the drawings for an unfinished mall in Lisbon crossed our designers’ desks, we were immediately intrigued by the opportunity to work in the sustainability-oriented “Silicon Valley of Europe.”

After rendering credit: Momentum.

The size of a city block, the four-story structure was primarily made of enormous slabs of concrete; a “donut hole” in the center was intended to be a quadruple height atrium.

Considering Lisbon’s recent growth in the tech industry, the KPF team and developers immediately recognized the large open floorplates as an opportunity to create the kind of flexible, expansive office space desired by technology and research companies. This was a chance to attract big international firms by creating a grade of office space that hadn’t existed in Lisbon.

Credit: Momentum.

With modern environmental performance targets in mind, this mall also represented an opportunity to create an office with a highly reduced level of embodied carbon by strategically retaining as much material as useful in the final design. For the design team, this meant undertaking the almost forensic pursuit of understanding every last element of the building. There is a learned art to this optimization practice—simply making an old building look new again won’t attract tenants, and certain things, such as the mechanical elements, had to be redone entirely.

Taking advantage of the “donut hole,” one of the major formal moves proposed by KPF was to open all the floors for ventilation and turn the center of the mall into an open courtyard. By peeling back walls and selectively opening up ceilings, the building became naturally ventilated and filled with light, bringing the project closer to its sustainability goals.

Finishing out the building with a new curvilinear roofline placed atop the now open roof deck, Oriente Green Campus will be an icon when completed. After presentation, the city of Lisbon approved it almost immediately.

Credit. Momentum.
Credit: Momentum.