About the Council

The Council on Tall Buildings and Urban Habitat, based at the Illinois Institute of Technology in CTBUH Journal Chicago and with a offi ce at Tongji International Journal on Tall Buildings and Urban Habitat University in Shanghai, is an international not-for-profi t organization supported by architecture, engineering, planning, development, and construction professionals. Founded in 1969, the Council’s mission is to disseminate multi- Tall buildings: design, construction, and operation | 2015 Issue I disciplinary information on tall buildings and sustainable urban environments, to maximize the international interaction of professionals involved Case Study: Bosco Verticale, Milan in creating the built environment, and to make the latest knowledge available to professionals in When Buildings Attack: Mitigating “Death Rays” a useful form. and : Skylines Comparison The CTBUH disseminates its fi ndings, and facilitates business exchange, through: the Sustaining a Historic High-Rise Structure publication of books, monographs, proceedings, and reports; the organization of world congresses, A Year in Review: 2014 Sets All-Time Records international, regional, and specialty conferences and workshops; the maintaining of an extensive Talking Tall: Kees Christiaanse website and tall building databases of built, under construction, and proposed buildings; the Ask a CTBUH Expert: Wind Turbines distribution of a monthly international tall building e-newsletter; the maintaining of an international resource center; the bestowing of annual awards for design and construction excellence and individual lifetime achievement; the management of special task forces/working groups; the hosting of technical forums; and the publication of the CTBUH Journal, a professional journal containing refereed papers written by researchers, scholars, and practicing professionals.

The Council is the arbiter of the criteria upon which tall building height is measured, and thus the title of “The World’s Tallest Building” determined. CTBUH is the world’s leading body dedicated to the fi eld of tall buildings and urban habitat and the recognized international source for information in these fi elds.

Council on Tall Buildings and Urban Habitat

S.R. Crown Hall Illinois Institute of Technology 3360 South State Street Chicago, IL 60616 Phone: +1 (312) 567 3487 Fax: +1 (312) 567 3820 Email: [email protected] http://www.ctbuh.org

ISSN: 1946 - 1186 Inside

News and Events Features 26 History, Theory & Criticism Frankfurt and Rotterdam: Skylines as Embodiment of a Global City In contrast to US cities, which allowed construction of in central 02 This Issue 48 Tall Buildings in Numbers urban areas, the post-World War II development of western Europe generally involved new construction in peripheral zones, while urban centers were mostly preserved or reconstructed to resemble their state before the war. As exceptions to the rule, Frankfurt and Rotterdam were rare European cities that Daniel Safarik, The Global Tall Building adopted high-rise buildings as main driving forces for the redevelopment of Nebojša Čamprag their central zones. These decisions set the conditions for the establishment of Figure 1. View of Frankfurt’s financial district. © Norbert Naegel. Figure 2. Fingerplan (1968) with Bankenviertel (framed in black) and zones for the powerful metropolitan images – communicated through skylines – that densification (shaded areas). Source: Müller-Raemisch, 1996: 212 Author these cities promote today. one hand, these structures are the modern municipality created a positive climate for Frankfurt high-rise was born. The double Nebojša Čamprag, Teaching and Research Associate successors to the fortifications that used to development in order to attract investors, towers of Deutsche Bank (1984) were the first Urban Design and Development Unit CTBUH Editor Picture: Impact of 2014 Introduction different media. The predominant features of gird the same area in medieval times. On the which is now recognized as one of the main constructed in this period, followed by Trianon Faculty of Architecture Technical University of Darmstadt skyscrapers, such as visibility, presence, and other hand, its spatial structure, with high- preconditions for the commencement of the (1993) and Japan Center (1996). Skyscrapers El-Lissitzky-Straße 1 64287 Darmstadt A global city is not merely a site of economic local/global domination, as well as strict rules rises organized around a central green area, early skyline. The first generation of high-rise generally became slimmer and taller, as transactions, but rather a place of global and requirements set forth by investors and bears a strong resemblance to the skyscrapers buildings, reaching up to 70 meters, began represented by the construction of t: +49 6151 16 7062 e: [email protected] imaginings (Short 2004). The idea of a “global the real-estate market, have often required surrounding Central Park in New York, if at a to emerge during the 1950s, taking tower by Foster + Partners in www.tu-darmstadt.de city” itself is a crucial factor in the contempo- the construction of such landmarks in far smaller scale. modest-sized, contemporary American and 1997, which is still the tallest building in the rary construction of the urban imagination, dedicated districts, in order to make both the classical pre-war German Modern buildings city and in Germany (see Figure 4). Nebojša Čamprag representing ”… an authorized image of city buildings and their districts economically as their role models (Alexander & Kittel 2006). Nebojša Čamprag is a teaching and research associate at the Faculty of Architecture, TU success” (Robinson 2006). This idea shapes feasible. Frankfurt and Rotterdam both have Becoming the City of High-Rises Development of the booming skyline was Darmstadt. He has a background in the history and images of cities, both through creation of multiple instances of such districts. Construction of the Zürich Haus in 1962 regulated by the High-Rise Development Plan 04 CTBUH Latest 50 Talking Tall: Kees Christiaanse theory of architecture and urbanism, urban planning and design, and in international cooperation in urban new symbolic meanings, and through spatial The historical conditions of the development marked the beginning of the second of 1999, which took into consideration the development. His research interests range from change powered by intense competition to of Frankfurt’s skyline were arranged after the generation of skyscrapers, characterized by a experiences of some other important global filtration of built heritage and construction of urban identities through heritage manipulation, to urban attract new investors, citizens, and tourists. “Mainhattan”: World’s Smallest Metropolis city was passed over as the site of the postwar sharp increase in height and the abundant cities, such as Paris and London, as well as of identity building through contemporary innovative federal capital. Its new economic strategy was use of international styles in various forms, Berlin, Munich, Vienna, and Boston, and architecture. His doctoral dissertation “Urban Identity Antony Wood, Taming Tall Buildings’ “Autistic” and Change – a Comparison Between Frankfurt The common image of a “global city ideal” is The image of Frankfurt as a city is to a large based on its long tradition in trade, banking, shapes, and contexts. To deal with evolving presented an urban design vision for the and Rotterdam,” published in 2014, deals with the often expressed through the skyline, as well degree synonymous with the silhouette of its and industry, with the intention of becoming construction dynamics, the city planning implementation of high-rise buildings into the problem of identity in contemporary cities and new means for establishing recognizable urban images. as through the never-ending challenge of skyscrapers (see Figure 1). Rapid at least the economic capital of the country, if authority proposed the Fingerplan in 1968 constructing “the world’s tallest building,” a transformation from “a city with some not of Europe. For this reason, the city (see Figure 2), which directed expansion powerful means of waging intercity high-rises” into “the city of high-rises” along the radially distributed main streets Executive Director Tendencies competition. Skyscrapers doubtlessly carry classified Frankfurt as a rarity among outside of the old city core. At the same many symbolic meanings, as they represent European cities, in that it supported a time, the first proposals to organize economic power and status. They are also concentration of high-rises in its central high-rises into a recognizable urban form easily perceptible in the Information Age, as zones. However, the implementation of a appeared, with the introduction of the a form of advertising supported through modern skyline in Frankfurt during the last Bankenplan/Clusterplan in 1970, which more 50 years has not been seamless. It has closely defined a high-rise area organized involved initial public rejection, as well as around the central green core of constant reviews, alterations, and partial Taunusanlage and Gallusanlage parks (see realizations of broad planning concepts. Figure 3). The most vigorous high-rise boom Despite its status and great importance to its occurred during the 1970s, when the “taboo” 05 Debating Tall: 53 Ask a CTBUH Expert: of 97 meters – the height of the Frankfurt The prime high-rise cluster in Frankfurt today “metropolitan image, the skyline in Frankfurt has is located within the Bankenviertel (banking Cathedral – was finally exceeded (Alexander district), named after its predominant & Kittel 2006). The most prominent buildings always carried some negative connotations, function. Many banks, insurance companies, to follow the Bankenplan/Clusterplan include Tall Timber in 10 Years? Jon Galsworthy and other financial institutions raised their the Euroturm (1977), Silberturm (1978), and although its mocking moniker Mainhattan headquarters in the zone located next to the the Citibank Tower (1984). historic center, gradually creating an gradually became widely accepted and turned unofficial urban district with loosely defined Along with the rise of the Postmodern style into an asset for urban branding and tourism. boundaries that are still expanding. On the Figure 3. Bankenplan/Clusterplan used by the City Plan- in architecture, the third generation of Figure 4. , Frankfurt. Wind Turbines on Tall Buildings ” ning Office until 1984. Source: Müller-Raemisch, 1996. © Marshall Gerometta 26 | History, Theory & Criticism CTBUH Journal | 2015 Issue I CTBUH Journal | 2015 Issue I History, Theory & Criticism | 27 06 Global News Highlights from the CTBUH Global News archive CTBUH 34 Retrofit Sustaining a Historic High-Rise Structure One of the tallest seismic retrofits in North America was undertaken in the …the new SLRS was capable of resisting heart of San Francisco. The Pacific Telephone & Telegraph Company headquar- th ters was an achievement of architecture of its day when completed in 1925, “100% of the seismic demands associated with and it remains an emblem of the Art Deco movement. The building’s current the specified seismic hazard. Story drifts were 54 CTBUH 13 Annual owner decided to embark on the challenging endeavor of reviving the historic structure. This meant preserving the historic fabric, creating an open, flexible generally low – less than 1.2% of the total Nina A. Mahjoub Megan Stringer workspace, and infusing state-of-the-art technology and sustainability into all height – except at the upper levels. Drifts at the its aspects, including a voluntary full seismic structural upgrade. Awards Events Report northwest corner were also slightly higher. Introduction capacity of the existing building system. Moreover, this approach allows the engineer the building now, one can quickly notice developer engaged a design team” in 2011 Case Study Situated in the heart of downtown San to better understand how the new and that the historic fabric of the structure has that would spend the next few years Francisco, the Pacific Telephone & Telegraph existing systems behave together during a stayed intact throughout the decades. following the guiding principles that would Daniel Safarik (PT&T) Company headquarters opened in seismic event, and therefore provides a restore and reinvigorate this iconic structure. Bill Tremayne 1925, reaching 132.7 meter and becoming smart, more sustainable, and less obstructive After housing one company for over 80 the tallest building in the city upon solution while maintaining the historic fabric Figure 1. 140 New Montgomery, San Francisco. years, the building was sold in 2008 to a real Some of the major work undertaken in this © Nathaniel Lindsey Authors completion (see Figure 1). The building, now of the building. estate developer. It was the refined character renovation have included the historic lobby Nina A. Mahjoub, ?????? known as 140 New Montgomery (140NM), (see Figure 2 and 3). The entrance houses an of the historic building that would set the rehabilitation, elevator modernization (to Megan Stringer, ?????? Bill Tremayne, Principal still stands as an icon of design and a Lastly, the paper discusses the environmental ornate and dramatic lobby with detailed tone for the project and the vision of its new support destination control), and entirely Holmes Culley San Francisco reminiscence of the power of the latest benefits of retrofitting versus rebuilding, and bronze doors, marble walls, and a hand- and proud owner. new mechanical, electrical, and plumbing 12 Case Study: Bosco Verticale, 235 Montgomery Street, Suite 235 San Francisco, CA 94104, United States technology of the time. how the sustainability objectives of the painted plaster ceiling by Mark Goodman systems designed with tenant controllability. t: +1 415 693 1600 project shaped the design. (see Figure 4). The entrance also leads to a The majority of the windows were replaced f: +1 415 693 1760 e: email 1 The building’s current owner since 2008, marble staircase. Project Vision and Goals with high-performance glazing and will 59 CTBUH on the Road http://www.holmesculley.com Wilson Meany, a real estate developer, remain operable to promote natural decided to embark on a challenging The Historic Building Since completion, the building has remained An article in San Francisco Newsweek from ventilation. Some exterior restoration of the Milan Nina A. Mahjoub endeavor of reviving the historic structure. relatively untouched, with a façade 1925 described 140NM as “the new building historic terracotta and historic glazed brick Nina Mahjoub is a Project Engineer at Holmes Culley, based in San Francisco, and was involved in the 140 While it will continue to host offices, the 140NM consists of a 26-story base, with a renovation in the 1980s and parapet bracing generation, a monument to Western façade was undertaken, which included New Montgomery project from schematic design building will now introduce state-of-the-art four-story tower above Level 27 and two installed just prior to the 1989 Loma Prieta progress and foresight.” Eight decades later, a repointing of joints and patching/repainting phase to construction completion. She holds a CTBUH events around the world technology in all aspects, including a basement levels, designed by Timothy earthquake. Comparing the building then to new developer was determined to continue individual units as necessary. Bachelor’s Degree in Civil Engineering from UCLA and a Master of Engineering High-Performance Structures voluntary structural system upgrade, while Pflueger and Frank Miller. When completed, this vision and honor its original inception as Elena Giacomello from MIT. She has more than five years of experience in New York City and California. Her projects have been maintaining the architect’s original intent. In 140NM became the tallest building in the a modern communication hub and a center focused on renovation, adaptive reuse and seismic addition to preserving the building’s historic city, until its height was matched by the of innovation. 140NM was going to continue retrofits of existing and historic buildings. features, Wilson Meany wanted to create a neighboring Russ Building two years later. housing the technology of tomorrow by

Megan Stringer healthy, sustainable space for its tenants and attracting creative entrepreneurs and Megan Stringer is a Project Engineer at Holmes Culley, targeted LEED Gold for the project. The building provided space for PT&T’s 2,000 companies in the tech sector, by providing based in San Francisco. She holds a Master’s Degree in Structural Engineering from the University of employees. The PT&T building was known them with state-of-the-art technology Texas at Austin. An active member in the sustainable This paper outlines the design goals of this nationally and internationally in the business infrastructure and flexible workspace within design community, she chairs the Structural upgrade: from the preservation of the and design communities, and was visited by a historic high-rise. To achieve that vision, the Diary Engineers Association of California’s Sustainable 59 Design Committee and is a member of ASCE’s SEI historic fabric to the creation of open flexible VIPs such as Winston Churchill, who in 1929 Sustainability Committee. She has presented at various conferences on sustainability and the role engineers office space, all while providing a safe and made one of the first Transatlantic phone play in shaping the built environment. sustainable structure in San Francisco’s calls from the building. unforgiving seismic environment. It also Bill Tremayne discusses the strengthening scheme The building is classified by the City of San Upcoming tall building events Bill Tremayne is a Principal & Technical Director at Holmes Culley, based in San Francisco. With more than evaluated and challenges faced during the Francisco as a Category I Historic Building 13 years of experience, he leads the firm’s practice of performance-based engineering, which has been design. It presents details on the analysis and is eligible to register for the National successfully applied to numerous seismic evaluation, method of the seismic retrofit, which utilized Register of Historic Places. Some of its retrofit and new building projects in the US and New Zealand. Bill is an ongoing contributor to the a performance-based design. This method historic features include 2.4 hectares of development of the masonry and analysis provisions presents the engineer with the capability to terracotta façade constructed by the of ASCE 41. look past conservative building codes and Gladding McBean Company, and eight Research determine in a more precise way the terracotta eagles perched atop the tower Figure 2. Terracotta façade along New Montgomery Figure 3. Eight terracotta eagles perched atop the 140 Figure 4. Historic Lobby Entrance. © Stephen Schafer Street. © Stephen Schafer NM. © Nathaniel Lindsey

60 Reviews 34 | Retrofit CTBUH Journal | 2015 Issue I CTBUH Journal | 2015 Issue I Retrofit | 35 20 When Buildings Attack Their Review of new books in the Neighbors: Strategies for CTBUH Library Protecting Against “Death Rays” 61 Comments 40 Vicente Montes-Amoros Feedback

26 Frankfurt and Rotterdam: 62 Meet the CTBUH Skylines as Embodiment of a James Parakh Global City Nebojša Čamprag 62 CTBUH Organizational Member Listing 34 Sustaining a Historic High-Rise Structure Nina A. Mahjoub, Megan Stringer, & Bill Tremayne

40 | A Year in Review: Tall Trends of 2014 CTBUH Journal | 2015 Issue I CTBUH Journal | 2015 Issue I A Year in Review: Tall Trends of 2014 | 41

40 A Year in Review: 2014 Sets All-Time Records

Increasingly complex geometries in buildings, in concert“ with a more elaborate palette of exterior materials, have exacerbated the effect of reflected light from glazed buildings.

” Vicente Montes-Amoros, page 20

CTBUH Journal | 2015 Issue I Inside | 3 Visit the daily-updated online resource for all the latest news on tall buildings, urban development, Global News and sustainable construction from around the world at: http://news.ctbuh.org

Americas

The last few months of 2014 saw intense activity on both the east and west coasts of North America and some major fireworks out of the US Midwest.

For decades, Miami has been the gateway for Latin American investors looking to grab a foothold in the city’s established high-rise condominium market. But recently, more mixed-use projects have come to the fore. In November, it was announced that the Worldcenter, a multi-building project downtown, would include a 60-story condo tower embedded in a three-level shopping mall that would span three city blocks. A 285-meter office/hotel/residential tower called the World Trade Center of the Americas – which would be the city’s tallest building if constructed – has been proposed for the popular Biscayne Boulevard strip. World Trade Center of America, Miami. © Arquitectonica 15 Hudson Yards, New York. © Related Meanwhile, the billion-dollar complex at space between two skyscrapers will be preventing the property from reverting to a Brickell City Center topped off the first of six constructed. In addition to the formal opening creditor. In November, daredevil Nik towers, a 40-story hotel, in December – and of with the arrival of Wallenda brought a worldwide TV audience significantly, the money is coming from Asia anchor tenant Conde Nast, another to the Chicago skyline when he tightrope- rather than Latin America. The project is being Manhattan megasite got some good news, as walked between the Marina City and Leo developed by Swire Properties of Hong Kong. resumed construction Burnett buildings across the Chicago River at upon securing sufficient leases and a a 15-degree angle, only to immediately cross Up the coast, New York continues to be an isle mortgage to support the issuance of US$1.6 between the two Marina City towers of surprises and superlatives. Construction billion in bonds. In Midtown, the planned One blindfolded. In December, as if in response to began on the 70-story 15 Hudson Yards, the Vanderbilt tower got a height boost from 441 the crushed ambitions for the Chicago Spire, first of a group of residential towers in the to 461 meters, which would put a new spin on a hugely ambitious three-tiered mixed-use US$20 billion megaproject being built over the superslim skyline now rising in the area. skyscraper was proposed almost directly rail yards that will transform the city’s across the river by China’s Wanda Group. The post-industrial West Side. Just across the Chicago, America’s skyscraper city on the Wanda Vista, designed by Studio Gang, street, the substantial Manhattan West “third coast” of Lake Michigan, had more than could rise up to 350 meters, placing it in the project announced the completion of its enough spectacle to compensate for the final top ranks of the city’s famous skyline. innovative platform over the tracks at the demise of the Chicago Spire project when its throat of Penn Station, upon which a public developer missed a critical deadline for

Brickell City Center, Miami. © Brickell City Center Nik Wallenda walked across the Chicago River. Source: ABC7

6 | Global News CTBUH Journal | 2015 Issue I THEY SAID

In China and in other parts of Asia, western architects continue“ to perform their one-off magic, while at the same time repeating many of the urban design catastrophes of the previous century, at significantly larger scales.

Steven Bingler, architect and Martin Pedersen,” architectural journalist in “How to Rebuild Architecture,” New York Times, December 15, 2014.

page 40). In keeping with this, in the latter quarter of the year, the majority of tall Wanda Vista, Chicago. © Studio Gang Architects Torre Costanera, Santiago. © Pablo Blanco building news came from Asia, and within the continent, China took the lead, though there In San Francisco, developer Forest City continent’s tallest at 335 meters. Construction was plenty of activity elsewhere to keep revealed plans for one of the largest projects on this project began in November and is due skyscraper-watchers satisfied. ever to be proposed in the city, covering 1.5 to complete by 2019. hectares and offering 130,000 square meters Construction began on Chengdu’s Greenland of space. To achieve this, a special-use district Tower, designed by + Gordon will be required to raise the towers beyond Asia and Oceania Gill and set to rise 468 meters with a mix of the area’s 49-meter height limit. office, hotel, and shopping uses. Greenland A record 74 buildings of 200 meters or higher also made the news in Yinchuan, where the South America welcomed its first supertall completed in 2014 – 76% of a global total of major developer selected John Portman & (300-meter-plus) building in the form of 97 – were in Asia (see 2014 Year in Review, Associates to design the Yinchuan Greenland Santiago, Chile’s Torre Costanera, which finished late last year. But it may not hold the title of South America’s tallest for long. Argentinian president Cristina Fernandez de Kirchner announced the awarding of a contract to build the Polo Audiovisual of Buenos Aires, which would become the

Greenland Tower Chengdu, Chengdu. Yinchuan Greenland Center. Polo Audiovisual of Buenos Aires. Source: Agency DyN © Adrian Smith + Gordon Gill Architecture © John Portman & Associates.

CTBUH Journal | 2015 Issue I Global News | 7 Case Study: Bosco Verticale, Milan A New Urban Forest Rises in Milan The Bosco Verticale “vertical forest” in Milan, Italy, takes the definition of “green skyscraper” to a new level, deploying more than 13,000 plants across 90+ species, including full-sized trees, on all façades of both its towers. The project was cited as a case study in the CTBUH 2014 Technical Guide Green Walls in High-Rise Buildings. In 2013, the CTBUH International Research Seed Funding Program, sponsored by Arup, awarded a grant of US$20,000 to a team led by Elena Giacomello the author of this paper, Dr. Elena Giacomello, which spent a year studying the Bosco Verticale, examining all aspects of its design and construction, Author especially the extensive plantings that give it its name. The full report will be Elena Giacomello, Professor Università Iuav di Venezia published in the forthcoming CTBUH research report: Bosco Verticale: Terese / Dorsoduro 2206 I-30123 Venezia Evaluating the Promise of Vertical Greenery. This case study introduces the Italy t: +39 041 257 1276 project and its many innovations. e: [email protected] www.iuav.it Introduction All the plants take root in containers located

Elena Giacomello on the external side of deep cantilevered Elena Giacomello, architect, graduated cum laude The Bosco Verticale in Milan supports one of terraces, which are accessible from each in architectural design from the Università Iuav di Venezia. the most intensive living green façades ever apartment. In 2011 she obtained her PhD in building technology realized. The combination of its sophisticated at the Università degli Studi di Ferrara, with an plant selection, the deployment of greenery Acting as an extension of the exterior experimental thesis entitled An Artificial Soil: the Role of Water in Green Roof Design, which was named as in all orientations, the structural design to envelope of the towers, the plants represent a the “best PhD thesis in building technology” of that accommodate the plants, and the filter between the interiors of the towers and year. The research analyzes the runoff regulation of green roofs through rain chamber tests and maintenance, safety and irrigation systems, the urban environment. From inside, the evaluates the benefits derived by application of represents one of the most innovative tall plantings offer inhabitants a special vegetated and draining built surfaces in the urban environment. building projects in recent memory. experience of their terraces, which are pleasantly shaded by luxuriant tree crowns, From 2011, Giacomello has been a professor of building technology and a temporary research fellow The Bosco Verticale consists of two and a “green-filtered view” to the city, in at Iuav. residential towers, 26 and 18 floors high addition to an enhanced feeling of privacy Recently, she completed a year-long monitoring respectively, characterized by the presence (see Figure 1). research project on Bosco Verticale, funded by the 2013 CTBUH International Research Seed Funding of dense vegetation along their outer program sponsored by Arup. envelopes (see Figure 2). There are about From outside, the plants realize an urban Her main research interest concerns technologies 13,000 plant specimens, including about 700 vertical reforestation, providing several that combine plants and construction. trees up to six meters high, on both towers. environmental and microclimate benefits particular to trees’ physiology: dust

Figure 1. Planters are located on each balcony.

12 | Bosco Verticale, Milan CTBUH Journal | 2015 Issue I absorption, pollution reduction, BVOC (Biogenic Volatile Organic Compounds) production, carbon sequestering, air temperature mitigation, and air humidity all increase or improve as an effect of evapotranspiration.

As result, the envelope of Bosco Verticale is an active interface to the environment, with a special architectural quality. The dynamism of plant life, in fact, is also expressed in the combination of forms and colors that derives from the carefully selected distribution of different species and specimens, which change over the seasons and the years. The greenery of the plantings is underscored by the grey color of the exterior walls, making the plants the protagonists of an architectural story of great visual, environmental, and ultimately, societal impact.

Site Conditions

The Bosco Verticale is part of the new Porta Nuova area, an extended urban transforma- tion of a neglected area of Milan. This 34-hectare area is completely new; before the construction of 20 towers in the last decade, it was one of the last unbuilt sites in the city. Before the Porta Nuova project began, the area was partially occupied by an amusement park; much of the remainder was abandoned, vestigial land.

In 2004, the urbanization project was Figure 2. Bosco Verticale, Milan. © Kristen Bucher approved and the available surface was arranged for a radical urban transformation, comprising an investment of more than €2 billion (US$2.51 billion) to create a mixed- business and residential district. The greenery of the plantings is emphasized The new Porta Nuova project is divided into “and underscored by the grey color of the exterior three neighborhoods: Isola, where the Bosco Verticale is located, Porta Garibaldi, and walls, making the plants the protagonists of an Varesine, taking advantage of its proximity to the city center. architectural story of great visual, environmental,

In addition to lying about 2,200 meters from and ultimately, societal impact. the main cathedral, excellent accessibility is ” provided by two nearby railway stations, two

CTBUH Journal | 2015 Issue I Bosco Verticale, Milan | 13 Façades When Buildings Attack Their Neighbors: Strategies for Protecting Against “Death Rays”

Some recent high-profile skyscraper designs that employ extensive exterior glass paneling have generated solar reflectivity, causing negative outcomes, such as melting plastic car parts and creating hazardous glare to neighboring buildings and nearby traffic. Solar reflectivity can also raise surface temperatures on adjacent properties and kill vegetation.

Vicente Montes-Amoros Building energy modeling can be invalidated if light reflected from neighbor- ing buildings is not taken into account. Today, Computational Fluid Dynamics Author (CFD) can be used to offer an accurate and advanced study that predicts not Vicente Montes-Amoros, Curtain Wall Design and Consulting, Inc. (CDC) only the location of reflected light, but also the intensity of these reflections 104 N. Bailey Lane Suite 202 Purcellville, Virginia 20132 and the related temperature increase originated by the reflected light. In this United States t: +1 540 751 1284 way, CFD can help designers limit solar reflectivity effects from their buildings. e: [email protected] www.cdc-usa.com Introduction The scope of this paper includes the portion

Vicente Montes-Amoros of the incident ray that is “bounced” back to Vicente Montes-Amoros is a structural and façade The undesirable designation of “death-ray the medium and will be referred to as engineer at CDC’s Virginia/Washington D. C. office. He has worked as a building envelope structural building” has a basis in history. Archimedes “reflection” from this point. Although engineer and specialized in the design and used an array of mirrors to set adversaries’ reflectivity issues are not exclusive to glass, engineering of different systems such as: natural stone, pre-cast concrete panels, composite panels, warships on fire during the Siege of Syracuse this paper focuses on glass due to its and a wide variety of glazing systems. He completed (214–212 BC). This piece of weaponry has predominant use in contemporary architec- a Master in Façade Engineering at the University of Bath, England. He started the solar reflectivity been known as “the Death Ray” ever since. ture. program at CDC, and has continued to work on its Today’s death rays emit from tall glazed development. He has published diverse articles on different building envelope topics, which have buildings earning them the nickname The reflected light’s directional behavior is been published in several building and construction “fryscrapers.” described by the reflection laws (see Figure 1): industry journals and magazines. ƒƒ The incident angle is equal to the reflected Basic optics laws tell us that when a light ray angle. travels in a medium and encounters a glass ƒƒ The incident ray, the reflected ray and the surface, for example, part of the incident ray line perpendicular to the surface (the is reflected and the rest is transmitted to the normal) are located on the same plane. other side of the glass. Depending on glass In Singapore, solar characteristics, the light transmitted exhibits With advances in technology and enough different ranges of phenomena such as computational power, these theories and “reflectance of heat-gain. Reflections produced by glass and principles that were developed over three other smooth and polished surfaces is called centuries ago, and which constitute the basis construction materials specular reflection. The reflection from rough of optics, can now be taken to a new level in surfaces is called diffuse reflection. the world of 3D applications. is limited to not more than 20%, and The Demand for Skyscrapers That Sparkle authorities have The built environment has seen an increased considered lowering demand for skyscrapers that maximize views through extensive exterior glass paneling. The that threshold to solar reflectivity phenomenon has generated attention lately due to the increase in heat 15%. Figure 1. Reflection law. Source: Tippens, P. 2005. Physics. that buildings can produce, which has ” New York: McGraw-Hill Science/Engineering/Math. 20 | Façades CTBUH Journal | 2015 Issue I resulted in significant property damage and theoretical temperature increase caused by and reflectance of construction materials were distracting glare. light reflected off buildings. limited. The analytical path would have applied if the previous factors were not We must remember that “light” is not only that Glare in the airspace can be also be predicted fulfilled and/or if the proposed design had which is visible, but that it comes in the form using this technique in order to comply with convex surfaces, which concentrate light. of thermal load. Light is comprised of different the civil aviation regulations for buildings and Unfortunately, this proposal did not survive components: ultraviolet (UV) radiation, visible structures at or near airports. For example, the beyond the public comment phase. light, and infrared. Light reflected off buildings US Federal Aviation Administration (FAA) carries all three components at different regulations require that no visual obstructions Due to the lack of legislation or industry scales, based on material properties. be allowed at the air traffic control tower or standards, this problem has not been along aircraft’s gliding slopes. Solar reflectivity successfully tackled in court. The cases of With the use of reflective glass, spectrally is considered an obstruction of safe opera- buildings that have produced severe damage selective coatings, and advanced glazing in tions at airports. CFD can measure glare in the or disputes regarding solar reflectivity have general, it is imperative to study solar airspace, which is something that other tools been addressed by the project’s design team reflectivity at a level that covers both visual lack today. or developers. This was the result of a recent and temperature increase effects in order to case in London, in which the 20 Fenchurch evaluate results on a project’s surrounding building’s concave shape cast concentrated environment. Legislation beams of light into neighboring streets (see Figuire 2), which were strong enough to melt Increasingly complex geometries in buildings, The last decade has seen an increased plastic mirrors and gaskets on cars. in concert with a more elaborate palette of number of adverse solar reflectivity cases, in exterior materials, have exacerbated the effect which buildings have “attacked” their of reflected light from some glazed buildings. neighbors, and their owners have been taken Solar Reflectivity Considerations Unfortunately, many designers have limited to court. However, many of the plaintiffs have their study of solar reflectivity by using found that the solar reflectivity nuisance has Solar reflectivity is a common phenomenon, rudimentary analytical tools that, while little or no enforcement precedents. Not only caused by the interaction between the providing an accurate prediction of the path are building codes silent on requirements for, reflective materials on the façades and the of reflected light, do not predict the intensity or limits on, reflectivity; there is also no structures around it (Shih & Huang 2000). It of this reflection. Such tools are limited to industry metric available for defining can produce discomfort, and can even be a single ray-tracing computations and can acceptable performance. threat to motor traffic when the light is typically be found in commercially available returned in the form of glare. design software as one of many built-in Most city building codes briefly and lightly functions. On the other hand, using CFD, one address solar reflectivity in the same sentence There are two glare types and two subtypes: can accurately predict the location of reflected as other types of nuisance such as noise, ƒƒ Discomfort glare is caused by two subtypes: light, the intensity of these reflections and the shadows, and bright paint colors. However, - Direct glare is a phenomenon originated there are two building codes internationally from light sources that cast luminance that deal with this matter more categorically. directly into the eye’s visual cone. In Singapore, solar reflectance of construction - Reflective glare occurs when light rays materials is limited to not more than 20%, and bounce off a surface and luminance is authorities have considered lowering that perceived from the angle of incidence of threshold to 15%. In Sydney, Australia, two the reflection. requirements must be fulfilled; reflectivity of ƒƒ Disability glare is a luminosity level change construction materials is limited to not more significant enough to reduce visibility of the than 20% and a solar reflectivity study/analysis observer. must be performed. Most of the cases dealing with the solar Driven by recent local events, the City of reflectivity of buildings are related to Dallas made an attempt to regulate this discomfort glare rather than disability glare phenomenon. In the proposed legislation, (Shih & Huang 2001). new construction and major retrofits had the option of addressing solar reflectivity on a Below are some of the factors that contribute prescriptive or an analytical path. To qualify to solar reflectivity’s negative effects on the Figure 2. London’s 20 Fernchurch Street’s façade reflects under the prescriptive path, building height urban environment: sun rays onto a nearby street. © Simon Price

CTBUH Journal | 2015 Issue I Façades | 21 History, Theory & Criticism Frankfurt and Rotterdam: Skylines as Embodiment of a Global City In contrast to US cities, which allowed construction of skyscrapers in central urban areas, the post-World War II development of western Europe generally involved new construction in peripheral zones, while urban centers were mostly preserved or reconstructed to resemble their state before the war. As exceptions to the rule, Frankfurt and Rotterdam were rare European cities that adopted high-rise buildings as main driving forces for the redevelopment of Nebojša Čamprag their central zones. These decisions set the conditions for the establishment of the powerful metropolitan images – communicated through skylines – that Author these cities promote today. Nebojša Čamprag, Teaching and Research Associate Urban Design and Development Unit Faculty of Architecture Introduction different media. The predominant features of Technical University of Darmstadt skyscrapers, such as visibility, presence, and El-Lissitzky-Straße 1 64287 Darmstadt A global city is not merely a site of economic local/global domination, as well as strict rules Germany transactions, but rather a place of global and requirements set forth by investors and t: +49 6151 16 7062 e: [email protected] imaginings (Short 2004). The idea of a “global the real-estate market, have often required www.tu-darmstadt.de city” itself is a crucial factor in the contempo- the construction of such landmarks in rary construction of the urban imagination, dedicated districts, in order to make both the Nebojša Čamprag representing ”… an authorized image of city buildings and their districts economically Nebojša Čamprag is a teaching and research associate at the Faculty of Architecture, TU success” (Robinson 2006). This idea shapes feasible. Frankfurt and Rotterdam both have Darmstadt. He has a background in the history and images of cities, both through creation of multiple instances of such districts. theory of architecture and urbanism, urban planning and design, and in international cooperation in urban new symbolic meanings, and through spatial development. His research interests range from change powered by intense competition to filtration of built heritage and construction of urban identities through heritage manipulation, to urban attract new investors, citizens, and tourists. “Mainhattan”: World’s Smallest Metropolis identity building through contemporary innovative architecture. His doctoral dissertation “Urban Identity and Change – a Comparison Between Frankfurt The common image of a “global city ideal” is The image of Frankfurt as a city is to a large and Rotterdam,” published in 2014, deals with the often expressed through the skyline, as well degree synonymous with the silhouette of its problem of identity in contemporary cities and new means for establishing recognizable urban images. as through the never-ending challenge of skyscrapers (see Figure 1). Rapid constructing “the world’s tallest building,” a transformation from “a city with some powerful means of waging intercity high-rises” into “the city of high-rises” competition. Skyscrapers doubtlessly carry classified Frankfurt as a rarity among many symbolic meanings, as they represent European cities, in that it supported a economic power and status. They are also concentration of high-rises in its central easily perceptible in the Information Age, as zones. However, the implementation of a a form of advertising supported through modern skyline in Frankfurt during the last 50 years has not been seamless. It has involved initial public rejection, as well as constant reviews, alterations, and partial realizations of broad planning concepts. Despite its status and great importance to its The prime high-rise cluster in Frankfurt today “metropolitan image, the skyline in Frankfurt has is located within the Bankenviertel (banking district), named after its predominant always carried some negative connotations, function. Many banks, insurance companies, and other financial institutions raised their although its mocking moniker Mainhattan headquarters in the zone located next to the historic center, gradually creating an gradually became widely accepted and turned unofficial urban district with loosely defined into an asset for urban branding and tourism.” boundaries that are still expanding. On the 26 | History, Theory & Criticism CTBUH Journal | 2015 Issue I Figure 1. View of Frankfurt’s financial district. © Norbert Naegel. Figure 2. Fingerplan (1968) with Bankenviertel (framed in black) and zones for densification (shaded areas). Source: Müller-Raemisch, 1996: 212 one hand, these structures are the modern municipality created a positive climate for Frankfurt high-rise was born. The double successors to the fortifications that used to development in order to attract investors, towers of Deutsche Bank (1984) were the first gird the same area in medieval times. On the which is now recognized as one of the main constructed in this period, followed by Trianon other hand, its spatial structure, with high- preconditions for the commencement of the (1993) and Japan Center (1996). Skyscrapers rises organized around a central green area, early skyline. The first generation of high-rise generally became slimmer and taller, as bears a strong resemblance to the skyscrapers buildings, reaching up to 70 meters, began represented by the construction of surrounding Central Park in New York, if at a to emerge during the 1950s, taking Commerzbank tower by Foster + Partners in far smaller scale. modest-sized, contemporary American and 1997, which is still the tallest building in the classical pre-war German Modern buildings city and in Germany (see Figure 4). as their role models (Alexander & Kittel 2006). Becoming the City of High-Rises Development of the booming skyline was Construction of the Zürich Haus in 1962 regulated by the High-Rise Development Plan The historical conditions of the development marked the beginning of the second of 1999, which took into consideration the of Frankfurt’s skyline were arranged after the generation of skyscrapers, characterized by a experiences of some other important global city was passed over as the site of the postwar sharp increase in height and the abundant cities, such as Paris and London, as well as of federal capital. Its new economic strategy was use of international styles in various forms, Berlin, Munich, Vienna, and Boston, and based on its long tradition in trade, banking, shapes, and contexts. To deal with evolving presented an urban design vision for the and industry, with the intention of becoming construction dynamics, the city planning implementation of high-rise buildings into the at least the economic capital of the country, if authority proposed the Fingerplan in 1968 not of Europe. For this reason, the city (see Figure 2), which directed expansion along the radially distributed main streets outside of the old city core. At the same time, the first proposals to organize high-rises into a recognizable urban form appeared, with the introduction of the Bankenplan/Clusterplan in 1970, which more closely defined a high-rise area organized around the central green core of Taunusanlage and Gallusanlage parks (see Figure 3). The most vigorous high-rise boom occurred during the 1970s, when the “taboo” of 97 meters – the height of the Frankfurt Cathedral – was finally exceeded (Alexander & Kittel 2006). The most prominent buildings to follow the Bankenplan/Clusterplan include the Euroturm (1977), Silberturm (1978), and the Citibank Tower (1984).

Along with the rise of the Postmodern style Figure 3. Bankenplan/Clusterplan used by the City Plan- in architecture, the third generation of Figure 4. Commerzbank Tower, Frankfurt. ning Office until 1984. Source: Müller-Raemisch, 1996. © Marshall Gerometta

CTBUH Journal | 2015 Issue I History, Theory & Criticism | 27 Retrofit / Seismic Sustaining a Historic High-Rise Structure One of the tallest seismic retrofits in North America was undertaken in the heart of San Francisco. The Pacific Telephone & Telegraph Company headquar- ters was an achievement of architecture of its day when completed in 1925, and it remains an emblem of the Art Deco movement. The building’s current owner decided to embark on the challenging endeavor of reviving the historic structure. This meant preserving the historic fabric, creating an open, flexible Nina A. Mahjoub Megan Stringer workspace, and infusing state-of-the-art technology and sustainability into all its aspects, including a voluntary full seismic structural upgrade.

Introduction capacity of the existing building system. Moreover, this approach allows the engineer Situated in the heart of downtown San to better understand how the new and Francisco, the Pacific Telephone & Telegraph existing systems behave together during a (PT&T) Company headquarters opened in seismic event, and therefore provides a Bill Tremayne 1925, reaching 132.7 meters and becoming smart, more sustainable, and less obstructive the tallest building in the city upon solution while maintaining the historic fabric Authors completion (see Figure 1). The building, now of the building. Nina A. Mahjoub, Project Engineer known as 140 New Montgomery (140NM), Megan Stringer, Project Engineer Bill Tremayne, Principal still stands as an icon of design and a Lastly, the paper discusses the environmental Holmes Culley San Francisco reminiscence of the power of the latest benefits of retrofitting versus rebuilding, and 235 Montgomery Street, Suite 235 San Francisco, CA 94104, United States technology of the time. how the sustainability objectives of the t: +1 415 693 1600 project shaped the design. f: +1 415 693 1760 e: [email protected]; The building’s current owner since 2008, [email protected]; Wilson Meany, a real estate developer, [email protected] http://www.holmesculley.com decided to embark on a challenging The Historic Building endeavor of reviving the historic structure.

Nina A. Mahjoub While it will continue to host offices, the 140NM consists of a 26-story base, with a Nina Mahjoub is a project engineer at Holmes Culley, building will now introduce state-of-the-art four-story tower above Level 27 and two and was involved in the 140 New Montgomery project from schematic design phase to construction technology in all aspects, including a basement levels, designed by Timothy completion. She holds a Bachelor’s Degree in Civil voluntary structural system upgrade, while Pflueger and Frank Miller. When completed, Engineering from UCLA and a Master of Engineering in High-performance Structures from MIT. She has maintaining the architect’s original intent. In 140NM became the tallest building in the more than five years of experience in New York City addition to preserving the building’s historic city, until its height was matched by the and California. Her projects have been focused on renovation, adaptive reuse, and seismic retrofits of features, the project team wanted to create a neighboring Russ Building two years later. existing and historic buildings. healthy, sustainable space for its tenants and targeted LEED Gold for the project. The building provided space for PT&T’s 2,000 Megan Stringer Megan Stringer is a project engineer at Holmes employees. The PT&T building was known Culley. She holds a Master’s degree in Structural This paper outlines the design goals of this nationally and internationally in the business Engineering from the University of Texas at Austin. An active member in the sustainable design community, upgrade: from the preservation of the and design communities, and was visited by she chairs the Structural Engineers Association of historic fabric to the creation of open flexible VIPs such as Winston Churchill, who in 1929 California’s Sustainable Design Committee and is a member of ASCE’s SEI Sustainability Committee. She office space, all while providing a safe and made one of the first Transatlantic phone has presented at various conferences on sustainability sustainable structure in San Francisco’s calls from the building. and the role engineers play in shaping the built environment. unforgiving seismic environment. It also discusses the strengthening scheme The building is classified by the City of San Bill Tremayne evaluated and challenges faced during the Francisco as a Category I Historic Building Bill Tremayne is a principal and technical director at Holmes Culley. With more than 13 years of experience, design. It presents details on the analysis and is eligible to register for the National he leads the firm’s practice of performance-based method of the seismic retrofit, which utilized Register of Historic Places. Some of its engineering, which has been successfully applied to numerous seismic evaluation, retrofit, and new a performance-based design. This method historic features include 2.4 hectares of building projects in the United States and New presents the engineer with the capability to terracotta façade constructed by the Zealand. Bill is an ongoing contributor to the development of the masonry and analysis provisions look past conservative building codes and Gladding McBean Company, and eight of ASCE 41. determine in a more precise way the terracotta eagles perched atop the tower

34 | Retrofit / Seismic CTBUH Journal | 2015 Issue I Some of the building’s historic features “include 2.4 hectares of terracotta façade constructed by the Gladding McBean Company, and eight terracotta eagles perched atop the tower. The entrance houses an ornate and dramatic lobby with detailed bronze doors, marble walls, and a hand- painted plaster ceiling by Mark Goodman.” now, one can quickly notice that the historic companies in the tech sector, by providing Figure 1. 140 New Montgomery, San Francisco. fabric of the structure has stayed intact them with state-of-the-art technology © Nathaniel Lindsey throughout the decades. infrastructure and flexible workspace within (see Figures 2 and 3). The entrance houses an a historic high-rise. To achieve that vision, the ornate and dramatic lobby with detailed After housing one company for over 80 developer engaged a design team in 2011 bronze doors, marble walls, and a hand- years, the building was sold in 2008 to a real that would spend the next few years painted plaster ceiling by Mark Goodman estate developer. It was the refined character following the guiding principles that would (see Figure 4). The entrance also leads to a of the historic building that would set the restore and reinvigorate this iconic structure. marble staircase. tone for the project and the vision of its new and proud owner. Some of the major work undertaken in this Since completion, the building has remained renovation includes the historic lobby relatively untouched, with a façade rehabilitation, elevator modernization (to renovation in the 1980s and parapet bracing Project Vision and Goals support destination control), and entirely installed just prior to the 1989 Loma Prieta new mechanical, electrical, and plumbing earthquake. Comparing the building then to An article in San Francisco Newsweek from systems designed with tenant controllability. 1925 described 140NM as “the new building generation, a monument to western progress, and foresight.” Eight decades later, a new developer was determined to continue this vision and honor its original inception as a modern communication hub and a center of innovation. 140NM was going to continue housing the technology of tomorrow by attracting creative entrepreneurs and

Figure 2. Terracotta façade along New Montgomery Figure 3. Eight terracotta eagles perched atop the 140 Figure 4. Historic Lobby Entrance. © Stephen Schafer Street. © Stephen Schafer NM. © Nathaniel Lindsey

CTBUH Journal | 2015 Issue I Retrofit / Seismic | 35 A Year in Review: Tall Trends of 2014

140

135 An All-Time Record 97 Buildings of 200 Buildings 200 Meters or Taller Completed Each Year from 1960 to 2016 130 Meters or Higher Completed in 2014 130 120 Report by Daniel Safarik and Antony Wood, CTBUH; Research by Marty Carver and Marshall Gerometta, CTBUH

110 Note: Please refer to “Tall Buildings in Numbers – 2014: A Tall Building Review” in conjunction with this paper, pages 48–49 110

105

the previous record high of 81 number of 200-meter-plus buildings in 100 The Council on Tall Buildings and Urban 97 Habitat (CTBUH) has determined that 97 completions in 2011. existence has hit 935, a 352% increase 1100 buildings of 200 meters’ height or greater from 2000, when only 266 existed. In the 2013 study (which was conducted 90 1,065 before the end of the year so as to release 1,040 1000 were completed around the world in 2014 ƒ A total of 11 supertalls (buildings of 300 Total Number of Buildings 200m+ in 935 the study at year end), CTBUH projected 73

900 buildings as having been completed in ƒ Existence in Each Decade from 1920 to 2015 81 – a new record (see Figure 3, opposite). meters or higher) completed in 2014 This was the “tallest year ever” by another 838 2013. That number has been revised to 71 80 this year, based on the following updates: 800 Further highlights: – the highest annual total on record. measure: The sum of heights of all 767 73 The Central Bank of Kuwait was originally listed Since 2010, 46 supertalls have been 200-meter-plus buildings completed 696 700 as having completed in 2013; however, no 71 71 information since the beginning of 2014 has ƒ The 97 buildings completed in 2014 beat completed, representing 54% of the across the globe in 2014 was 23,333 70 615 600 validated this. The completion date for this every previous year on record, including supertalls that currently exist (85). The meters – setting another all-time record building has now been revised to 2015. 500 The Aiqun Towers (1 and 2) of Guangzhou, China and breaking 2011’s previous record of were included in the original 2013 total. Since 60 400 then it has been determined that the buildings 19,852 meters. are actually 192 meters high, which removes the 60 58 14,000 13,549 2014 Completions: 200m+ Buildings by Country buildings from the 200m+ sample. 13,549 Number of buildings 200 m+ completed each year 300 266 Note: One tall building 200m+ in height was also completed during 13,000 Added to 2013 Completion List: 50 13,000 50 48 2014 in these countries: Chile, Kuwait, Malaysia, Singapore, South Korea, ƒ Asia’s dominance of the tall building industry 200 The ASE Center R2 in Chongqing, China, was 50 50 Taiwan, United Kingdom, Vietnam 147 completed in 2013 but was not confirmed at the increased yet again in 2014. Seventy-four of 105 time of the 2013 study. This has now been 87 100 5,000 71 68 77 102 confirmed, and thus added retroactively to the 5,000 50 59 28 the 97 buildings completed in 2014, or 76%, 15 11 24 2013 completions list. 40 2 6 11 11 3 5 1 1 2 2 2 3

40 ) 0

40 ) were in Asia. 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2011 2012 2013 2014 2015 (m (m

Total Number (Total = 97) 4,000 s Total Number (Total = 97) 4,000 s 32 ht ht er 31 31 er Sum of Heights (Total = 23,333 m)

mb 30 30

mb 30 Heig

Heig 27

ƒ Once again, for the seventh year in a row, Nu of Nu 3,000

3,000 of 25

Total Number of Countries = 19 m 23 Total Number of Countries = 19 m China completed the most 200-meter- 22 Su 20 Su 20 19 2,000 plus buildings (58, see Figure 1). This 20 18 18 18 2,000 17 17 represents 60% of the global 2014 total, 15 15 1,143 1,145 13 13 13 1,143 1,115 1,145 10 11 11 800 756 1,000 and a 61% increase over its previous 10 679 712 756 9 9 9 9 5 503 532 10 8 8 8 4 4 503 532 402 7 7 3 3 3 3 402 record of 36 in 2013. 6 6 6 6 2 22 5 5 5 4 4 4 4 3 3 3 3 3 3 3 3 3 0 0 2 2 2 2 2 2 2 2 2 2 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 China Philippines Qatar UAE Canada Indonesia Japan United Australia Saudi Turkey 1 1 1 China Philippines Qatar Canada Japan United Australia Saudi 0 States Arabia ƒ The Philippines took second place with 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2011 2012 2013 2014 2015 Figure 1. 2014 completions by country. fi ve completions, the United Arab 2010 2016 Emirates and Qatar share position three Notes: 2014 Completions: 200m+ Buildings by City 2014 Completions: 200m+ Buildings by City with four completions, and the United Number of 200 m+ buildings Projected number of 200 m+ buildings 1. We can predict 2015–2016 building completions with some Note: One tall building 200 m+ in height was also completed during 2014 in these cities: accuracy due to projects now in advanced construction. A Note: One tall building 200 m+ in height was also completed during 2014 in these cities: States, Japan, Indonesia, and Canada tie range is given to indicate the challenging factors in Brisbane, Busan, Changsha, Foshan, Haikou, Hanoi, Harbin, Istanbul, Izmir, Jeddah, Jinan, Number of supertalls (300 m+) Projected number of supertalls (300 m+) Kuala Lumpur, Kunming, Kuwait City, Liuzhou, London, Manila, Melbourne, Nanjing, Nanning, predicting building completion dates. 6 Kuala Lumpur, Kunming, Kuwait City, Liuzhou, London, Manila, Melbourne, Nanjing, Nanning, for fourth, with three completions each. 6 Nantong, Osaka, Riyadh, Santiago, , Singapore, Taipei, Taiyuan, Zhengzhou 1,300 6 1,245 m 1,300 2. Totals after 2001 take into account the destruction of the 1,221 m Number of megatalls (600 m+) Projected number of megatalls (600 m+) World Trade Center Towers 1 and 2.

1,145 m ƒ Japan marked its first entry into the 5 Total Number (Total = 97) 1,100 Figure 3. The amount of 200 m+ buildings completed each year from 1960 to 2016. 5 supertall stakes with the completion of Sum of Heights (Total = 23,333 m)

906 m the 300-meter Abeno Harukas in Osaka, 4 8804 m 4 4 900

4 ) 4 Total Number of Cities = 54 ) 800 becoming the country’s tallest building. China, along with Doha, Qatar, all tied for ƒ At 541 meters, One World Trade Center predominant structural material is (m (m s 703 m 712 m s 703 m 712 m ht second place with four completions each was the tallest building to complete in concrete dropped to 38% in 2014, from ht er 677 er 677 679 m 700 3 3 3 3 3 3 679 m 659 m 700

mb 3

mb 3 605 Heig

605 Heig ƒ South America also welcomed its fi rst (see Figure 2). 2014 and is now the world’s third- 61% in 2013.

576 m 576 m 571 m Nu of Nu of 496 m 496 m 454 m 476 m 480 m m supertall, the 300-meter Torre Costanera of tallest building. 467 m 462 m 459 m 454 m 476 m 480 m 500 m 467 m 456 m 462 m 2 2 459 m 4562 m 500 2 2 2 2 2 2 2 2 2 2 222 2 Su 2 2 2 2 2 2 420 2 2 222 Su 2 420 410 Santiago, Chile, which was also the only ƒ In 2014, 47 all-offi ce buildings were ƒ All-steel continued its decline as a ƒ 300 building of 200 meters or greater to completed (48% of the total), the largest A majority of 2014 completions used primary structural material, comprising 1 complete on the continent in 2014. total ever, versus 31 (38% of the total) in composite construction as the primary only 5% of 2014’s 200-meter-plus

100 2011, the previous record high. structural system – 52 out of 97 (54%), completions and 13% of the world’s 100

0 0 ƒ Tianjin, China, was the city that as compared to 24 out of 71 (34%) in tallest buildings, though it showed a

Doha Wuxi Dubai Hefei Tokyo completed the most 200 m+ buildings, 2013. The number of buildings whose slight uptick from 3% in 2013. Tianjin DohaWuhan Jakarta Beijing DubaiFuzhou Hefei Makati TokyoXiamen Wuhan Jakarta Toronto BeijingChengdu Fuzhou HuzhouMakati Qingdao Xiamen Hangzhou Nanchang Abu Dhabi Chengdu QingdaoShanghaiShenyang Chongqing GuangzhouHangzhou Nanchang Abu Dhabi with six. Chongqing, Wuhan, and Wuxi, New York City Mandaluyong Figure 2. 2014 completions by city.

402 | | A A Year Year in in Review: Review: Trends Tall Trends of 2011 of 2014 CTBUH Journal | 20122015 IssueIssue I I CTBUH Journal | 2012 Issue I A Year in Review: Trends of 2011 | 3 140

135 Buildings 200 Meters or Taller Completed Each Year from 1960 to 2016 130 130

120

110 110

105

100 97

1100 In the 2013 study (which was conducted 90 1,065 before the end of the year so as to release 1,040 1000 Total Number of Buildings 200m+ in 935 the study at year end), CTBUH projected 73

900 buildings as having been completed in Existence in Each Decade from 1920 to 2015 81 838 2013. That number has been revised to 71 80 this year, based on the following updates: 800 767 73 The Central Bank of Kuwait was originally listed 696 700 as having completed in 2013; however, no 71 71 information since the beginning of 2014 has 70 615 600 validated this. The completion date for this building has now been revised to 2015.

500 The Aiqun Towers (1 and 2) of Guangzhou, China were included in the original 2013 total. Since 60 400 then it has been determined that the buildings are actually 192 meters high, which removes the buildings from the 200m+ sample.

Number of buildings 200 m+ completed each year 300 266 Added to 2013 Completion List: 50 50 48 200 The ASE Center R2 in Chongqing, China, was 147 completed in 2013 but was not confirmed at the 105 time of the 2013 study. This has now been 87 100 71 68 77 102 confirmed, and thus added retroactively to the 50 59 28 15 24 2013 completions list. 40 2 6 11 11 3 5 11 1 1 2 2 2 3 0 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2011 2012 2013 2014 2015

32 31 31 30 27

25 23 22

19 20 18 18 18 17 17 15 15 13 13 13 11 11 10 9 9 9 9 10 8 8 8 7 7 6 6 6 6 5 5 5 4 4 4 4 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 2012 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2011 2013 2014 2015 2010 2016

Notes: Number of 200 m+ buildings Projected number of 200 m+ buildings 1. We can predict 2015–2016 building completions with some accuracy due to projects now in advanced construction. A Number of supertalls (300 m+) Projected number of supertalls (300 m+) range is given to indicate the challenging factors in predicting building completion dates. Number of megatalls (600 m+) Projected number of megatalls (600 m+) 2. Totals after 2001 take into account the destruction of the World Trade Center Towers 1 and 2. Figure 3. The amount of 200 m+ buildings completed each year from 1960 to 2016.

China, along with Doha, Qatar, all tied for ƒ At 541 meters, One World Trade Center predominant structural material is second place with four completions each was the tallest building to complete in concrete dropped to 38% in 2014, from (see Figure 2). 2014 and is now the world’s third- 61% in 2013. tallest building. ƒ In 2014, 47 all-offi ce buildings were ƒ All-steel continued its decline as a completed (48% of the total), the largest ƒ A majority of 2014 completions used primary structural material, comprising total ever, versus 31 (38% of the total) in composite construction as the primary only 5% of 2014’s 200-meter-plus 2011, the previous record high. structural system – 52 out of 97 (54%), completions and 13% of the world’s 100 as compared to 24 out of 71 (34%) in tallest buildings, though it showed a 2013. The number of buildings whose slight uptick from 3% in 2013.

CTBUH Journal || 20122015 Issue Issue I I A YearA Yearin Review: in Review: Tall Trends Trends of of 2014 2011 | | 41 3 Tall Buildings in Numbers The Global Tall Building Picture: Impact of 2014

In 2014, a total of 97 buildings of 200 meters or higher were completed, more than in any previous year, and a 20% increase from the previous record of 81, set in 2011. Not surprisingly, 60% of these 2014 buildings were in China. Perhaps more counterintuitively, 2014 saw an apparent reversal in the decline of all-office buildings, and a significant drop in all-concrete buildings, while the United States claimed its first tallest worldwide completion since 2009. For more analysis of 2014 completions, see “A Year in Review: Tall Trends of 2014,” pages 40–47.

World’s Tallest Building Completed Each Year 800 m Starting with the year 2000, these are the tallest buildings completed globally each year. 828 m/2,717 ft One World Trade Center Dubai 541 m/1,773 ft New York 700 m Shanghai World Financial Center Makkah Royal Clock Tower Hotel 492 m/1,614 ft 601 m/1,972 ft Shanghai Mecca

600 m Trump International Hotel & Tower JW Marriott Marquis 508 m/1,667 ft 423 m/1,389 ft Hotel Dubai Tower 2 KK100 Taipei Chicago 355 m/1,116 ft 442 m/1,449 ft Dubai Years Average Shenzhen 500 m 2013 394 Emirates Tower One Two International Finance Centre 355 m/1,163 ft 412 m/1,352 ft Shimao International Plaza 2012 388 Dubai Hong Kong 333 m/1,094 ft Shanghai 2011 374 400 m Rose Rayhaan 2010 366 Menara Telekom Tower by Rotana 323 m/1,058 ft 310 m/1,017 ft 333 m/1,093 ft Gold Coast 2009 344 Kuala Lumpur 302 m/992 ft Dubai Riyadh 2008 339 300 m 800 m 2007 331 2006 329 2005 327 200 m 700 m Years Average2004 325 Average - Yearly Completions 2015 365 2003 320 Years Average 2014 350 2002 317 2015 245 100 m 600 m 2013 344 2001 316 2014 241 2012 341 2000 315 2013 241 2011 331 1999 310 2012 250 500 m 2010 323 2011 245 2001 2011 2014 2000 2002 2003 2004 2005 2006 2007 2008 2009 2010 2012 2013 2009 307 2010 255 The Average Height of the Tallest Buildings 2008 304 2009 230 400 m 2008 245 The average height of the 100 tallest buildings in existence around the world that year 2007 297 The average height of all 200 m+ buildings completed that year 2007 236 Tallest 100: 2006 295 Tallest 100: Tallest 100: Tallest 100: 344 meters 350 meters Tallest 100: 341 meters 2006 237 331 meters 2005 292 300 m Tallest 100: Tallest 100: 323 meters Tallest 100: Tallest 100: Tallest 100: Tallest 100: 304 meters 307 meters 2005 228 Tallest 100: Tallest 100: Tallest 100: Tallest 100: 297 meters 2004 290 290 meters 292 meters 295 meters 285 meters 286 meters 284 meters 286 meters 2010 Average: 2012 Average: 2003 286 2004 247 2000 Average: 2004 Average: 2008 Average: 255 meters 2011 Average: 2013 Average: 2014 Average: 2003 Average: 2006 Average: 2007 Average: 250 meters 243 meters 2001 Average: 247 meters 2005 Average: 245 meters 2009 Average: 245 meters 241 meters 241 meters 2002 Average: 233 meters 237 meters 236 meters 73 Buildings 71 Buildings 2003 233 23 Buildings 227 meters 18 Buildings 228 meters 48 Buildings 230 meters 81 Buildings 2002 284 200 m 223 meters 27 Buildings 32 Buildings 71 Buildings 97 Buildings 31 Buildings 31 Buildings 50 Buildings 23 Buildings 16 Buildings 2001 283 2002 223 2000 281 2001 227 2001 2011 2000 2002 2003 2004 2005 2006 2007 2008 2009 2010 2012 2013 2014 2015 1999 277 2000 243

25,000 m 1999 246

Amidst much fanfare, One World 2014 marks the second year in 20,000 m The sum of all the Trade Center, New York City, at a row that at least 75% of all 200 m+ buildings 541 m height, was the tallest 200 m+ building completions 15,000 m completed in

building completed in 2014, Asia were located in Asia 10,000 m 2014 was 23,333 (76%) also becoming the third-tallest 76% in 2014 meters, the tallest building in the world 75% in 2013 5,000 m year in history 2010 = 18,579 m 2011 = 19,852 m 2012 = 17,757 m 2012 = 17,113 m 2014 = 23,333 m 0 m

482 | | A Tall Year Building in Review: in Numbers Trends of 2011 CTBUH Journal | 20122015 IssueIssue I I World’s Tallest 100: Analysis As the graphs below show, we continue to see major shifts towards Asia, mixed-use function, and composite structures.

100 100 100 100 100 6 3 6 3 10 9 9 5 4 3 3 11 16 8 3 3 4 5 98 5 3 3 6 8 12 98 98 9 4 4 3 4 96 95 23 33 39 3 22 30 6 93 92 13 4 3 3 3 5 4 31 11 89 89 5 89 12 87 88 88 87 87 36 85 80 80 25 9 80 80 79 11 36 43 18 67 44 60 60 60 21 41 59 55 43 51

40 40 40 41 39

29 20 20 20 20 21 13

0 0 1930 1940 1950 1960 1970 1980 1990 2000 2010 2014 1930 1940 1950 1960 1970 1980 1990 2000 2010 2014 1940 2000 2010 1930 1950 1970 1990 1960 1980 2014 100 tallest buildings by location 100 tallest buildings by function 100 tallest buildings by material

North America Asia Middle East Europe Office Mixed-use Steel Concrete Composite

South America Australia Central America Africa Hotel Residential Mixed Unknown

Number of Buildings Entering the World’s 100 Tallest by Year Though 2014 was the most active year ever for completions of 200-meter-plus buildings, with 97 buildings, only 13 entries made it into the 100 Tallest in the world. The year 2011 saw the greatest number of buildings entering the 100 tallest list, at 18.

18 18

16 16

14 14

13 13

12 12 12 12 12

11 11

10 10 10

9 9

8 8 8 8 8 8 8

7 7 7 7

6 6 6 6

5 5 5 5 5 5 5

4 4 4 4 4 4 Number of buildings entering the World’s 100 Tallest Buildings List Tallest 100 World’s the Number of buildings entering 4

3 3

2 2

1

25 cities completed at least South America’s fi rst Similarly, Japan’s fi rst supertall, two 200 m+ tall buildings in supertall, Torre Costanera, Abeno Harukas, Osaka, 300 m, 2014, the highest of all time, Chile, 300 m, entered the entered the World’s 100 Tallest showing the increasing global World’s 100 Tallest Buildings Buildings list at position 85; The demand for tall buildings. list at position 84; It is only other Japanese building 2007 had the second-highest the only South American on the list is Landmark Tower, total, with 17 cities building on the list Yokohama, 296 m

CTBUH Journal || 20122015 Issue Issue I I A Year inTall Review: Building Trends in Numbers of 2011 | | 49 3 Talking Tall: Kees Christiaanse Taming Tall Buildings’ “Autistic” Tendencies The CTBUH is actively expanding the “Urban Habitat” portion of its mission, which calls for tall buildings to be optimally integrated into human-scaled urban environments. Reflecting this mission, CTBUH Editor Daniel Safarik recently spoke to Kees Christiaanse, principal of KCAP Architects & Planners. The firm has offices in Rotterdam, Zurich, and Shanghai, and has extensive experience in urban master plans throughout Europe and Asia, as well as Kees Christiaanse having designed numerous individual tall buildings in those contexts. These include the districts of HafenCity, and Wijnhaven Island, Rotterdam, Interviewee where KCAP’s Red Apple, a 2009 CTBUH Award-nominated tall building, is Kees Christiaanse, Founder KCAP Rotterdam located. Piekstraat 27, 3071 EL Rotterdam I’m very interested in the concept that your plot size and the urban ensemble of tall Postbus 50528, 3007 JA Rotterdam The firm has developed called “flexible buildings. In many cases, tall building t: +31 10 7890 300/301/302 urbanism.” That has a very appealing sound ensembles are footprint developments that f: +31 10 7890 309 e: [email protected] to it. Can you define it in your own words? have a very autistic relationship with public www.kcap.eu If you work in the city and you work within a space. For instance, they only have one larger context, you will soon learn that entrance over a whole block. They are often Kees Christiaanse everything that you draw that you think is blind in the sense that they have basements Kees Christiaanse studied architecture and urban planning at TU Delft. From 1980 until 1989, he fixed will be changed over time. These days, or parking garages on their façades. That’s worked for the Office for Metropolitan Architecture when there are such enormous and rapid not a good condition to develop urban (OMA) in Rotterdam, becoming a partner in 1983. In 1989, Christiaanse founded his own office, Kees transformations in economies and urban quality. There is a direct relationship between Christiaanse Architects & Planners in Rotterdam, contexts, it’s no use to work on designs that plot size typology – on hand – and known as KCAP since 2002. From 1996 until 2003 he taught architecture and urban planning at TU Berlin, are inflexible and fixed. It’s necessary to work urban vibrancy. Let’s say we always try to Germany. Since 2003, he has been a professor at the in a more strategic way, to work in a way of work in high-rise conditions to give them ETH in Zurich, Switzerland. In 2009, Christiaanse was curator of the International Architecture Biennale control and laissez-faire, in which you define smaller footprints, so they have to arrange Rotterdam (IABR) with the title Open City: Designing certain things that you assume are robust, and themselves in relation to other plots. This Coexistence. Since 2010, Christiaanse has been program leader of the Future Cities Laboratory (FCL) leave other things open. This makes you more creates an emerging friction where they in Singapore. like a director and less of a sculptor. I think this settle themselves and are given much more is a vital difference between an architect and grounding in the urban fabric. an urban designer. The architect always ends up creating his own confined product within Connected to that is the idea of a podium. the brief and the site that he’s got and Many modernist towers still stand as shafts according to his own fine taste, but the urban on the ground without any public space or designer has to coordinate between courtyards. You see that most urban vibrancy everybody’s bad tastes and make something develops in conditions with clear fronts and out of it. So it’s a radically different way of backs, and clearly indefinite spaces that can working if you want to do it right. You also be colonized by uses. This is something that have to very clearly study impacts of urban a lot of those buildings don’t have. design in order to get feedback and identify if your designs will have an impact or not. Then of course, you have the traditional American problem, where there are building [As an urban Tall buildings are often accused of being regulations that allow enormous floor plates. “designer] you have to contextless, immutable, and hostile to the These aren’t allowed in Europe, because street. You’ve designed several very there are daylight rules that limit large cores. have a very hard head, interesting tall buildings that fit within their This initially looks very economical, but in the environments and many more urban plans end it is very inflexible, because it means that because you are that incorporate others’ tall building these building can be used in no other way designs. What do you think is essential in than as large offices. If you take into account constantly punched in order to facilitate “flexible urbanism” in that that the life cycle of buildings is increasingly the nose. context? short, then these enormous floor plates are ” What is very important is the relation between not very sustainable in terms of flexibility. 50 | Talking Tall: Kees Christiaanse CTBUH Journal | 2015 Issue I You also see that gradually people are looking for either smaller footprints or modulated plans, where there is much more exposure to the outside. It’s also very important to take into account where the cores are, in order to have a semblance of flexibility.

As a master planner, do you feel that you are able to get the appropriate level of flexibility out of local codes when you are working with authorities in different countries? In many cases not. Unfortunately, the urban designer is someone who has a lot of power, but also is completely powerless. This unstable condition is often reflected in an urban design, which means that certain aspects you Figure 1. HafenCity, Hamburg. © Reinhard Kraasch. Source: Wikipedia cannot control, such as if a mayor comes and says, “I’m going to do this, and despite your Some have criticized that certain buildings would certainly build the project, because the design I’m going to change it.” You have to in that development, like the fees are significant. That led to an incremental have a very hard head, because you are Elbphilharmonie, were expensive and too kind of development, in which every project constantly punched in the nose. You have to slow to finish. that started was secured because the building give up principles, not because you are It’s just one building, which is not part of the permit was handed in. That’s also why it is compromising, but because there is no HafenCity budget. Apparently it eats up part both a large-scale and small-scale project. choice. People just go over you. This is a basic of the cultural budget of the city, which is aspect of urban planning which you shouldn’t quite damaging, although in 10 years nobody Are there standalone projects that you also conceive as something personal, but as a will talk about it anymore. Another stagnating think were successful? consequence of urban development being project in HafenCity is the middle section, The The second project of ours that I think is very the result of so many people, influences, and Überseequartier, which, contrary to the other successful is this tower project in Rotterdam, forces of power. The direction that it goes projects, was tendered as one big project at the Red Apple (see Figure 2). This is a single sometimes is not predictable. If you do not 300,000 square meters. This has caused building within an urban design that we like this kind of unpredictability, then you are problems. The Dutch investment banks pulled in the wrong business. back after the economic crisis because they weren’t allowed to go into real estate We have a lot of problems with mayors in anymore. cities that have romantic, and short-sighted legislation-oriented ideas of how the city The German developer was too small to do it should be. This is very damaging sometimes, by himself, and had never done such a big but it’s all in the game. I would say that out of project, and almost went bankrupt on it. In 10 projects, one project is OK as it is realized. the end there was no commitment after a little bit less than two-thirds was constructed. What do you think were some of the most After it was completed, the main shopping successful projects that integrated the street was still unfinished, so the shops within verticality of tall buildings with a humanis- the development got into difficulties, because tic, flexible urban design as you intended? there was no circulation. It’s a snowball effect. I think our HafenCity Hamburg project (see Figure 1) is really the most successful, but this The main part of HafenCity was developed is due to the politics that were very enlight- block by block. Sometimes there were two or ened. The management of the HafenCity three building sites that were organized as Corporation consisted of extremely well competitions for design-build teams. When educated and insightful people. somebody won, they only got the land and property from the moment they handed in the building permit request, that is, when they paid the fees to the city. This meant that they Figure 2. Red Apple, Rotterdam. © KCAP

CTBUH Journal | 2015 Issue I Talking Tall: Kees Christiaanse | 51 About the Council

The Council on Tall Buildings and Urban Habitat, based at the Illinois Institute of Technology in CTBUH Journal Chicago and with a China offi ce at Tongji International Journal on Tall Buildings and Urban Habitat University in Shanghai, is an international not-for-profi t organization supported by architecture, engineering, planning, development, and construction professionals. Founded in 1969, the Council’s mission is to disseminate multi- Tall buildings: design, construction, and operation | 2015 Issue I disciplinary information on tall buildings and sustainable urban environments, to maximize the international interaction of professionals involved Case Study: Bosco Verticale, Milan in creating the built environment, and to make the latest knowledge available to professionals in When Buildings Attack: Mitigating “Death Rays” a useful form. Frankfurt and Rotterdam: Skylines Comparison The CTBUH disseminates its fi ndings, and facilitates business exchange, through: the Sustaining a Historic High-Rise Structure publication of books, monographs, proceedings, and reports; the organization of world congresses, A Year in Review: 2014 Sets All-Time Records international, regional, and specialty conferences and workshops; the maintaining of an extensive Talking Tall: Kees Christiaanse website and tall building databases of built, under construction, and proposed buildings; the Ask a CTBUH Expert: Wind Turbines distribution of a monthly international tall building e-newsletter; the maintaining of an international resource center; the bestowing of annual awards for design and construction excellence and individual lifetime achievement; the management of special task forces/working groups; the hosting of technical forums; and the publication of the CTBUH Journal, a professional journal containing refereed papers written by researchers, scholars, and practicing professionals.

The Council is the arbiter of the criteria upon which tall building height is measured, and thus the title of “The World’s Tallest Building” determined. CTBUH is the world’s leading body dedicated to the fi eld of tall buildings and urban habitat and the recognized international source for information in these fi elds.

Council on Tall Buildings and Urban Habitat

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