CTBUH Journal International Journal on Tall Buildings and Urban Habitat

Tall buildings: design, construction and operation | 2012 Issue II

Capital Gate, Abu Dhabi Securing Iconic Structures Environmental Performance of the TTDI Developing ’s Skyline Talking Tall: The Index Debating Tall: Is UNESCO Going Too Far? Tall Buildings in Numbers: Occupiable Telecommunication & Observation Towers Inside

News and Events CTBUH 12 Case Study: Capital Gate, Abu Dhabi “From the beginning of concept design, the reflecting the building’s proximity to the water • Four hundred and ninety foundation piles and the city’s sea-faring heritage. were driven 20 to 30 meters underground architects and engineers integrated many By integrating with the National Day to support the structure and counter Grandstand – one of Abu Dhabi’s most stresses. The piles, which were initially in passive and active sustainable systems into compression during construction to 02 This Issue historic structures – Capital Gate underscores 46 Helsinki: Developing a Finnish support the lower floors of the building, are the bond between the traditional and Capital Gate, its most visible sustainable modern that is characteristic of Abu Dhabi’s now in tension as the stresses caused by Jeff Schofield feature is the “splash,” which twists around the developmental approach. the overhang have been applied. • The vertical and horizontal cross-sections of Author the tower are all unique Steve Watts, CTBUH Trustee Vernacular for the High-rise? Jeff Schofield, Associate building towards the south to shield itself as First of its Kind RMJM • Asymmetric shape – no two rooms are the Floor 27, Monarch Office Tower much as possible from direct sunlight.” There are several innovations within the same (see Figure 2); every single pane of PO Box 6126 project’s design, including the dramatic Dubai the 12,500 panes of glass on the façade is a UAE Throughout history, a strong link has existed between iconic architecture and exhibitions. 18-degree westward lean, which has earned it different size although each pane is Antony Wood t: +971 4 702 7626 One of the best known examples is Paris’ Eiffel Tower, which was built as a visual symbol of the the title of “world’s furthest leaning man- triangular f: +971 4 329 6444 Exposition Universelle, World’s Fair of 1889. More recently cities like Seville have used made tower” from the Guinness book of world e: [email protected] • Floor plates change shape and orientation www.rmjm.com powerful and innovative architecture as a way to highlight the cultural significance of their records (see Figure 1). It is also the first exhibitions. building in the world to use a pre-cambered to create the distinctive “overhang” moving from “curved triangular” to “curved Jeff Schofield core with a built-in lean of 350 04 CTBUH Latest Since moving to RMJM Dubai in 2005, Jeff Schofield rectangular,” while increasing in overall size The Concept aesthetic splendor and technical excellence to millimeters that has been has lent his design expertise to a variety of large scale engineered to straighten with and migrating from east to west as they building developments, including mixed use, In 2005, the Abu Dhabi National Exhibitions celebrate human achievement and reflect the hospitality and high-rise projects. the addition of the upper progress up the tower Company (ADNEC) was created to drive dynamism of Abu Dhabi. As an Associate at RMJM, Jeff leads the effort in floors. And it is the first building • Capital Gate is one of few buildings in the providing sustainable solutions to all design projects in forward the development of Abu Dhabi’s Capital Gate is the result. in the world to use vertical world that use a diagrid structure; it also the office. He has developed a holistic approach to events sector. Plans were created with RMJM Antony Wood, 48 CTBUH Young Professionals design that integrates sustainability, structure and The tower’s curvaceous shape draws strongly post-tensioning of the core to features two diagrid systems, an external architectural expression with the built form, in order to to build a state-of-the-art exhibition centre on the sea and desert – two elements that counter movement and diagrid defining the tower’s shape and an provide meaningful solutions for high-quality building which would be the largest in the Gulf region designs. Jeff seeks to design in a contemporary yet have great resonance in Abu Dhabi. The support stresses created by internal diagrid linked to the central core by contextual manner, to create modern sustainable and provide world class facilities for live events building’s form is meant to represent a buildings using the latest technology. the building’s overhang. eight unique pin jointed structural to flourish in Abu Dhabi. swirling spiral of sand, while the curved CTBUH Executive Director Committee Launches Jeff currentlygy lives and works in Dubai. He began his The construction also members. career in New York City and pursupursueded his prprofessionaofessional It was strongly felt that the entire canopy, known as the “splash,” which runs over adopted a variety of • All 8,250 steel diagrid members are prapractice for momorere than 15 yyearsears in PariParis,s, FraFrannce. JJeffeff hahass development required a signature tower, a the adjoining grandstand and rises on one projecttm managementmanagement anandddd ddesignesign expexperienerienceoe oonnan a leading-edge approaches to different thicknesses, length and rangerange of high profile prproojects. Jeff hahass specific cutting-edge structure with a futuristic design, side of the building, creates a wave-like effect, experienexperiience inin sustainabsustaini abble designdesiign andd proproject create the desired result, orientation ® managementmanagementot ooff largarge-se-sescalepe ppubublic projects thrthroughoutoughout including: Ambitious Agenda Europe,Europe, U.S.A and the Middle East. 05 Debating Tall: Is UNESCO Kevin Brass Going Too Far? 49 CTBUH Research

06 Global News Development Initiative: Figure 1. Typical section © ADNEC Figure 2. Typical hotel floor plan © ADNEC 12 | CapCapitapitiitatatal Gate,Gateaatttee,,A AbuAbub DhDhabihhaabibi CTBBUHUUHH JouJJournaouournarnrnanal | 2020111 IssueIIssssusueueue IIII CTBUH Journal | 2011 Issue II Capital Gate, Abu Dhabi | 13 Highlights from the CTBUH An Update global news archive Payam Bahrami

51 CTBUH on the Road 18 Securing Iconic Structures “In sophisticated urban planned environments, designer with understanding the exposure to which could have been avoided, if only be a key to minimizing negative interactions CTBUH events around the threats. For example, a building near a designers had taken a more open-minded with security. Site confusion can lead to anger. security should be subtle, but allow for the proposed or existing mall will make criminal approach during the design process. Roadways are integral to the project, but incidents more likely. In similar fashion, simple and cost effective techniques, such as Case Study potential for heightened threats. The key is to integrating a train or metro into a large using a serpentine access road, can create high-rise project could increase exposure to Preparing for the Future elegant and effective solutions to reduce the world. find a suitable balance between security and chemical or explosive attacks, while the To prepare for tomorrow’s uncertainties, potential for a vehicle to approach a building Sean Ahrens Stephen Yas preserving the designer’s vision. A security creation of a building near a government today’s international planners should start by at high speed. facility or embassy may escalate the tertiary evaluating the site and potential setbacks and Counter terrorism and counter surveillance Authors terrorism risk. standoff distances from the façade of the techniques are extremely beneficial to Sean A. Ahrens, Practice Leader/Manager program for any structure should employ a The type of building and its tenants may also building. Even with constricted site layouts, identifying an aggressor. For this reason, Aon Fire Protection Engineering there are opportunities that can be explored. Security Division variety of controls to deter, delay, detect, deny affect risk rating, which can change over time. building layout, whenever applicable, should 1000 Milwaukee Avenue, 5th floor Understanding the risks early in the process Setback can be achieved through a number afford natural sight lines to allow the Glenview, IL 60025 and respond to threats, as well as mischievous of programming elements. To increase the 12 Capital Gate, Abu Dhabi United States will assist organizations in making decisions. detection of an intruder. As a result, affect of clear space, the perception of setback t: +1 847 461 9359 The planner should ensure that the security landscaping is extremely important. Trees and f: +1 847 953 7793 or potential accidental acts.” analysis provides specific guidance and can be somewhat masked through other foliage that can obscure sight lines 51 Diary [email protected] architectural programming, such as the www.aonsecurity.com This paper emphasizes the importance of integrating security programming into building recommendations on vehicular access, should be discouraged. Lighting, the number design, allowing for different uses and threat levels for the life of the building. Security security placement of cameras, access control creation of multi-tiered planting areas, water one deterrent to crime, may become features, structures and natural boulders. The Jeff Schofield Stephen Yas strategies will be evaluated that can be applied to any building, as well as review procedures and the overall security compartmentalization obscured by growing tree canopies. As a , Design Principal proposed US Embassy in London employs an MulvannyG2 (Shanghai) Architecture to address concerns early in the design process, especially in politically and economically program. result, lighting plans and photometric should Ciro’s Plaza Suite 1905 charged international environments. General concepts and approaches to building security enveloped glass façade and a water feature to take into account tree growth over the life of Upcoming tall building events 388 Nanjing Xi Road From a security perspective, designers need support security. The water feature provides a Shanghai 200003 will be examined, demonstrating the benefit of collaboration between architects and security to think about the “what-ifs.” They need to the tree and the effect on the light China visual element to the project, but it also professionals at an early stage to meet the project’s goals without detracting from the have a vision. That does not necessarily mean distribution. By doing this more effective light t + 86 21 6032 0100 planner’s vision for the project. creates a defined perimeter and clear zone. placement can be identified. f + 86 21 6217 8525 implementing controls from day one, but e: [email protected] designing provisions into the architecture so When developing building placement, Hotels will often employ a porte cochere, www.mulvannyg2.com The “Fortress” When planning a facility, design professionals security controls can be easily and quickly roadways should be carefully evaluated. which can expand setback from the primary need to think outside-the-box. Although fear To the untrained eye, this graphic (see Figure adopted in the future if higher threat Centralized or limited roadway access is structure while providing continuity in Sean A. Ahrens of terrorism typically drives the mindset for 1) may appear “fortress” like. However, in its scenarios arise. preferred, while incorporating standards and architecture and limit the perception of Sean leads the security consulting practice at Aon FPE iconic building security, there are other more with over 19 years of experience, a majority of which most basic format, the diagram describes the requirements for emergency access. In some distance from the entry to the building. likely threats, including workplace violence, The downside of shortsighted preplanning is has been in a security consulting function. He has been security program for building at any security cases, emergency access roadways will need Setback is more than maintaining vehicle responsible for providing security threat and risk evident in the airports built 20 years ago. The 52 Reviews level. Early dialogue between security domestic spill over issues, intellectual theft, to be secured and may create a conflict with analysis, contingency planning, loss prevention, and proximity, setback increases natural lines of property theft and other malicious acts functions and usage of airports have changed force protection design and planning. Sean has professionals and the designer can limit the first responders. Proper signage and clear sight as well as the area that must be provided design and construction administration for against persons or property that can affect the dramatically. The free flowing public government, public, and private entities that fortress or bunker aesthetic by careful access routes can limit frustration by people traversed prior to accessing a facility, while building and its occupants. Unforeseen environment of yesterday is now a series of encompass telecommunications, security, surveillance, placement of technical security, including who are not familiar with the site, which could supporting the potential for early detection of and access control systems. He is well versed in the dangers can create significant security mazes and security compartmentalization various trade and local authority issues impacting cameras, setbacks, gates, fencing and spatial an aggressor. Designs should limit Review of new books in the projects, and has specialized professional competence challenges for building owners post-design provisions for security staffing. Research in security, access control systems, and force components that may be used by aggressors and may detract from the marketing, image protection systems. for criminal acts. Loose rocks of substantial In many cases, consideration is not given to and status of the project. Planning for a single size could be used to break windows to gain the potential for a future modification to the threat may not be effective and may miss Stephen Yas entry to a building or be picked up as a building, such as the addition of a casino, potential threats in the future. The best Stephen has over 35 years experience working makeshift weapon in an ambush scenario. If CTBUH Library internationally. He specializes in architecture, urban parking garage, skate park or theater, which approach is to create generalized controls design and interior design for large mixed-use may increase the potential for malevolent rocks are integral to design, they should be projects. As design principal in the Shanghai office of designed to address a broad range of threats. MulvannyG2 Architecture, he is the design leader in acts. The addition of new tenants, such as a kept small or be large enough that they can’t china for the firm. Prior to MulvannyG2, Stephen leads dignitary or VIP, may require a change in the Unlike other building elements, there are no be easily picked up. his own firm in Chicago for 22 years. Prior to that he standards for the provision of security based was a senior designer at SOM Chicago and Lohan security status not considered in the original Associates, as well as working in England and the design process. The modification of the on building occupancy. As a result, the 18 Securing Iconic Structures Middle East. The Worst Case Scenario physical and architectural security component evaluation and development of security is the most important, most expensive and, controls is purely based on a quantitative risk When designing setback and site placement, therefore, most difficult to modify post-design. and consequence analysis which evaluates all consideration should be equally afforded to Done early in the design process there is aspects of the proposed building, not simply the planning for emergency vehicles and 52 CTBUH in the Media such critical assets as electrical and Sean Ahrens & Stephen Yas significant indirect and direct return on muster points for evacuating tenants. Muster investment that can be achieved by pre- telecommunications systems. Conducting a points need to account for the expected mass risk and consequence analysis will assist the planning. Figure 1. The “fortress” © Aon of people and should be as far away from ®

Selection of media coverage 18 | Securing Iconic Structures CTBUH Journal | 2011 Issue II CTBUH Journal | 2011 Issue II Securing Iconic Structures | 19 24 The Environmental Performance of the TTDI 53 Comment Suraksha Bhatla & Joanna Feedback on the past journal Gonçalves issue 32 Developing Rotterdam’s Skyline “The framework as presented carries the literature, however, often neglects the western European cities possess this type of Rotterdam’s semi-official tall building history substantial impact and their visual mature skyline: London, Paris, Frankfurt, and portrays a 100-year prelude from the late 19th potential to underpin a city’s guidance on tall footprint can have on urban life. “The Rotterdam. century, with the completion of the 42-meter significance of these buildings – in terms of The leading position of Rotterdam is Witte Huis, built in 1898, to the so-called “first building development. This framework presents height, levels of human occupancy, aesthetic furthermore underscored by DEGW’s report wave” of high buildings in the mid-1980s. impact and popular representation and use on London’s Skyline, Views, and High Buildings Prominent city planners suggest that the city the context of a tall building design, providing a – is in need of careful geographical commissioned by the Greater London at the turn of the century was on the verge of 53 What’s on the CTBUH Web? Frank van der Hoeven Steffen Nijhuis interpretation.” (McNeill 2005) Authority (GLA). The London policy document a “second wave” of tall buildings, which would 32 Developing Rotterdam’s more balanced evaluation of a design proposal feature supertall buildings (Maandag 2001). In 2007 the Institute for Spatial uses the same four European cities to Authors compared to studies that focus solely on Research (Lörzing et al. 2007) published an compare established European practices of However, this tale cannot be underpinned Frank van der Hoeven, Associate Professor with facts. Neither the height nor the location Steffen Nijhuis, Assistant Professor investigation on the visibility of the proposed tall buildings policymaking: London, Paris, individual tall buildings.” Belle van Zuylen tower. At 262 meters the Frankfurt, and Rotterdam. of the high buildings dating from this early Featuring new content now Delft University of Technology period relate to the municipal policy on Skyline Faculty of Architecture Belle van Zuylen tower would become The tall building policy document that high-rises. It was only in the 1970s that the Julianalaan 134 The planning and construction of tall buildings is often controversial, polarizing the public Holland’s tallest residential building and the 2628 BL Delft emerged in the Netherlands is called current tall building area in the middle of the The Netherlands debate on architecture and urban life. In many cases the emotional discourse focuses on centerpiece of Leidsche Rijn, the new city hoogbouwbeleid or hoogbouwvisie. The Dutch city center began to emerge. t: +31 15 278 9805 aesthetics and view corridors, more than city planning or economics. This paper introduces a district, west of Utrecht. But the Netherlands policies resemble a number of policy e: [email protected] framework that analyzes the visual impact a developing skyline has on a city and its Institute for Spatial Research analysis showed Essential data on tall buildings can be easily available on the website e: [email protected] documents recently produced in the United Frank van der Hoeven & www.graduateschool.abe.tudelft.nl surrounding region, using Rotterdam as a case study. By studying the height and completion that the Belle van Zuylen could be seen from presented by means of a scatter plot. In the Kingdom and Germany. year, identifying the tall building cluster as it is perceived visually and conducting a GISc- most of the “Green Heart,” the semi-rural case of Rotterdam, the building height and Height regulation is a key component of all Frank van der Hoeven based visibility analysis, the framework provides context to tall building designs. The results region enclosed by the cities of Rotterdam, the year of completion were plotted, Prof. van der Hoeven is an associate professor of urban make the assessment of individual projects more scientific and balanced, removing many of Amsterdam, The Hague and Utrecht. The these tall building policies. Height also including the primary use of such buildings. design at the Faculty of Architecture at the Delft translates into visibility. University of Technology, the Netherlands. He the emotional elements that often enter into the discussions. report was the last blow for the proposed The beauty of Rotterdam’s scatter plot lies in Steffen Nijhuis conducted his PhD research in the field of development – construction was cancelled the clear patterns that emerge. In her book underground space technology and multifunctional A modern history and intensive land-use. The core of his work deals with Introduction Concerns about the appropriateness of tall soon after the release of the report (Lörzing Form Follows Finance, Carol Willis explains Over the years, the city of Rotterdam has urban design issues related to mixed-use Research on the visual impact of tall buildings buildings in the urban environment, the 2011). that the end of a tall building wave is typically development: transit-oriented development, urban quality of the architecture and the impact on carefully cultivated an image as a “city of greenhouse horticulture, the use of underground has the potential to make or break a tall The Belle van Zuylen case is a fine example of marked by the construction of the “tallest 54 Meet the CTBUH space, high-rise urban areas and climate change. local real estate markets is increasingly architecture.” But “historic” architecture is not building so far.” If we would consider these building proposal. In the UK, debates over the using research for tactical purposes through Currently he combines his associate professorship in reflected in municipal and metropolitan Rotterdam’s strong point. Few buildings were urban design with the position of Director of Research appropriateness of projects in London and the selective presentation of findings. The “tallest buildings so far” as anomalies and of the Faculty of Architecture. policymaking. Prominent cities with a left standing after the bombing and fire of Liverpool are focused on view corridors, with study did not present the Belle van Zuylen in disregard them, the development of the longstanding tradition of urban management, May 1940. The few buildings that survived UNESCO threatening to remove world its true context. The joint visual impact of all Rotterdam tall building cluster is characterized Steffen Nijhuis building regulations and zoning plans often were relatively modern buildings from the heritage designations from historic complexes the tall buildings in the region on the Green by a remarkable continuity. However, if Carol Kevin Brass Prof. Nijhuis is an assistant professor of landscape feel the need for additional instruments to 1920s and 1930s. The city had to rebuild its architecture at Delft University of Technology (the if the new developments damage their Heart was not considered, nor how much that Willis’ insights are applicable to Rotterdam, Netherlands). His PhD research, entitled “Landscape control the development of what is described center from scratch. Planners seized this aesthetic impact (see “Debating Tall”). impact would change as a result of the then the year in which the tallest building so Architecture and GIS,” focuses on the application of by McNeill as “an extremely complex spatial opportunity to experiment with architecture geographic information science in landscape construction of the Belle van Zuylen. If the far was completed could be used as the architectonic research and design. The core of his work phenomenon” (McNeill, 2005). Scientific and urbanism, which is why the Rotterdam breaking points between tall building waves. deals with theories, methods and techniques in the study had included these elements, it may not city center now contains numerous field of landscape architecture and urban design, have caused such stir. In fact, a nearby Three such buildings stand out in Rotterdam: visual landscape assessment and visual knowledge monuments and icons from the modern and the Faculty of Medicine of the Erasmus representation. He is leader of the architecture and television tower, the 367-meter modernist period, sometimes referred to as landscape research program, series editor of RiUS and Gerbrandytoren tower, built 42 years earlier, University, also known as Hoboken (1969, 112 advisor to governmental and regional authorities in “reconstruction architecture.” meters), the (1991, 93 and 151 the Netherlands. dominates the visual impact of the area. Features Discussions about the appropriateness of tall meters) and the (2009, 165 meters). 55 CTBUH Organizational A framework that helps to picture the context buildings surfaced from time to time, but If the tall building history of Rotterdam is of a proposed tall building can potentially never reached the emotional levels indeed characterized by waves, then these neutralize public and political debates that so experienced in cities with a historic center. Tall buildings are indicative of three such waves, often lead to polarization. This framework is buildings are now generally accepted and as represented in the scatter plot (see Figure based on three key elements: most are concentrated in the city center. 2). The end of the wave is determined by the Structure & Member Listings While Rotterdam as a whole uses modern and latest and tallest building in a development Rotterdam’s tall building development modernist architecture to promote itself, tall cycle. Rotterdam is one of the prominent European buildings are an essential ingredient in the tall building cities with a mature tall building A first wave of tall building construction profile of the city: the skyline, including the began in Rotterdam in the early 1970s and a 38 Tall Buildings in Numbers policy in place (see Figure 1). Several famous Erasmus Bridge, has become the city’s second wave followed in the late 1980s and databases, including the CTBUH’s The iconic image (Ulzen 2007). Skyscraper Center, make it clear that only four early 1990s. This second wave is not only Figure 1. Rotterdam as a prominent west European tall building city © authors defined by architectural height. The ®

A Look at Occupiable 30 | Developing Rotterdam’s Skyline CTBUH Journal | 2011 Issue II CTBUH Journal | 2011 Issue II Developing Rotterdam’s Skyline | 31 Telecommunication & Observation Towers “Although commonly classified as a typology of high-energy 40 Design Research University of Nottingham demand, tall buildings can be beneficial in hot, humid climates. Considering both urban and building scales, the 42 Talking Tall: The Skyscraper Index typology enhances the exposure of the built form to wind Andrew Lawrence flow, generates more wind at the ground level and provides desirable shadows upon the immediate surroundings. ” Suraksha Bhatla & Joanna Gonçalves, page 24

CTBUH Journal | 2012 Issue II Inside | 3 Developing Rotterdam’s Skyline

“The framework as presented carries the potential to underpin a city’s guidance on tall building development. This framework presents the context of a tall building design, providing a Frank van der Hoeven Steffen Nijhuis more balanced evaluation of a design proposal Authors Frank van der Hoeven, Associate Professor compared to studies that focus solely on Steffen Nijhuis, Assistant Professor individual tall buildings.” Delft University of Technology Faculty of Architecture Julianalaan 134 The planning and construction of tall buildings is often controversial, polarizing the public 2628 BL Delft The Netherlands debate on architecture and urban life. In many cases the emotional discourse focuses on t: +31 15 278 9805 aesthetics and view corridors, more than city planning or economics. This paper introduces a e: [email protected] framework that analyzes the visual impact a developing skyline has on a city and its e: [email protected] www.graduateschool.abe.tudelft.nl surrounding region, using Rotterdam as a case study. By studying the height and completion year, identifying the tall building cluster as it is perceived visually and conducting a GISc- Frank van der Hoeven based visibility analysis, the framework provides context to tall building designs. The results Prof. van der Hoeven is an associate professor of urban make the assessment of individual projects more scientific and balanced, removing many of design at the Faculty of Architecture at Delft University of Technology, the Netherlands. He conducted his PhD the emotional elements that often enter into the discussions. research in the field of underground space technology and multifunctional and intensive land-use. The core of his work deals with urban design issues related to Introduction Concerns about the appropriateness of tall mixed-use development: transit-oriented Research on the visual impact of tall buildings buildings in the urban environment, the development, urban greenhouse horticulture, the use quality of the architecture and the impact on of underground space, high-rise urban areas and has the potential to make or break a tall climate change. Currently he combines his associate building proposal. In the UK, debates over the local real estate markets is increasingly professorship in urban design with the position of reflected in municipal and metropolitan Director of Research of the Faculty of Architecture. appropriateness of projects in London and Liverpool are primarily focused on view policymaking. Prominent cities with a Steffen Nijhuis corridors, with UNESCO threatening to longstanding tradition of urban management, Prof. Nijhuis is an assistant professor of landscape remove world heritage designations from building regulations and zoning plans often architecture at Delft University of Technology, The feel the need for additional instruments to Netherlands. His PhD research, entitled “Landscape historic complexes if the new developments Architecture and GIS,” focuses on the application of damage their aesthetic impact (see Debating control the development of what is described geographic information science in landscape by McNeill as “an extremely complex spatial architectonic research and design. The core of his work Tall, page 5). deals with theories, methods and techniques in the phenomenon” (McNeill, 2005). Scientific field of landscape architecture and urban design, visual landscape assessment and visual knowledge representation. He is leader of the architecture and landscape research program, series editor of RiUS and advisor to governmental and regional authorities in the Netherlands.

Figure 1. Rotterdam as a prominent west European tall building city

32 | Developing Rotterdam’s Skyline CTBUH Journal | 2012 Issue II literature, however, often neglects the western European cities possess this type of Rotterdam’s semi-official tall building history substantial impact skyscrapers and their visual mature skyline: London, Paris, Frankfurt, and portrays a 100-year prelude from the late 19th footprint can have on urban life. “The Rotterdam. century, with the completion of the 42-meter significance of these buildings – in terms of The leading position of Rotterdam is Witte Huis, built in 1898, to the so-called “first height, levels of human occupancy, aesthetic furthermore underscored by DEGW’s report wave” of high buildings in the mid-1980s. impact and popular representation and use on London’s Skyline, Views, and High Buildings Prominent city planners suggest that the city – is in need of careful geographical commissioned by the Greater London at the turn of the century was on the verge of interpretation.” (McNeill 2005) Authority (DEGW 2002). The London policy a “second wave” of tall buildings, which would In 2007 the Netherlands Institute for Spatial document uses the same four European cities feature supertall buildings (Maandag 2001). Research (Lörzing et al. 2007) published an to compare established European practices of However, this tale cannot be underpinned investigation on the visibility of the proposed tall buildings policymaking: London, Paris, with facts. Neither the height nor the location Belle van Zuylen tower. At 262 meters the Frankfurt, and Rotterdam. of the high buildings dating from this early Belle van Zuylen tower would become period relate to the municipal policy on The tall building policy document that high-rises. It was only in the 1970s that the Holland’s tallest residential building and the emerged in the Netherlands is called centerpiece of Leidsche Rijn, the new city current tall building area in the middle of the hoogbouwbeleid or hoogbouwvisie. The Dutch city center began to emerge. district, west of Utrecht. But the Netherlands policies resemble a number of policy Institute for Spatial Research analysis showed documents recently produced in the United Essential data on tall buildings can be easily that the Belle van Zuylen could be seen from Kingdom and Germany. presented by means of a scatter plot. In the most of the “Green Heart,” the semi-rural case of Rotterdam, the building height and region enclosed by the cities of Rotterdam, Height regulation is a key component of all the year of completion were plotted, Amsterdam, The Hague and Utrecht. The these tall building policies. Height also including the primary use of such buildings. report was the last blow for the proposed translates into visibility. The beauty of Rotterdam’s scatter plot lies in development – construction was cancelled the clear patterns that emerge. In her book soon after the release of the report (Lörzing A modern history Form Follows Finance, Carol Willis explains 2011). Over the years, the city of Rotterdam has that the end of a tall building wave is typically The Belle van Zuylen case is a fine example of carefully cultivated an image as a “city of marked by the construction of the “tallest using research for tactical purposes through architecture.” But “historic” architecture is not building so far.” If we would consider these the selective presentation of findings. The Rotterdam’s strong point. Few buildings were “tallest buildings so far” as anomalies and study did not present the Belle van Zuylen in left standing after the bombing and fire of disregard them, the development of the its true context. The joint visual impact of all May 1940. The few buildings that survived Rotterdam tall building cluster is characterized the tall buildings in the region on the Green were relatively modern buildings from the by a remarkable continuity. However, if Carol Heart was not considered, nor how much that 1920s and 1930s. The city had to rebuild its Willis’ insights are applicable to Rotterdam, impact would change as a result of the center from scratch. Planners seized this then the year in which the tallest building so construction of the Belle van Zuylen. If the opportunity to experiment with architecture far was completed could be used as the study had included these elements, it may not and urbanism, which is why the Rotterdam breaking points between tall building waves. have caused such stir. In fact, a nearby city center now contains numerous Three such buildings stand out in Rotterdam: television tower, the 367-meter monuments and icons from the modern and the Faculty of Medicine of the Erasmus Gerbrandytoren tower, built 42 years earlier, modernist period, sometimes referred to as University, also known as Hoboken (1969, 112 dominates the visual impact of the area. “reconstruction architecture.” meters), the Delftse Poort (1991, 93 and 151 meters) and the Maastoren (2009, 165 meters). Discussions about the appropriateness of tall A framework that helps to picture the context If the tall building history of Rotterdam is buildings surfaced from time to time, but of a proposed tall building can potentially indeed characterized by waves, then these never reached the emotional levels neutralize public and political debates that so buildings are indicative of three such waves, experienced in cities with a historic center. Tall often lead to polarization. This framework is as represented in the scatter plot (see Figure buildings are now generally accepted and based on three key elements: 2). The end of the wave is determined by the most are concentrated in the city center. latest and tallest building in a development While Rotterdam as a whole uses modern and Rotterdam’s Tall Building Development cycle. modernist architecture to promote itself, tall Rotterdam is one of the prominent European buildings are an essential ingredient in the A first wave of tall building construction tall building cities with a mature tall building profile of the city: the skyline, including the began in Rotterdam in the early 1970s and a policy in place (see Figure 1). Several famous Erasmus Bridge, has become the city’s second wave followed in the late 1980s and databases, including the CTBUH’s The iconic image (van Ulzen 2007). early 1990s. This second wave is not only Skyscraper Center, make it clear that only four defined by architectural height. The 

CTBUH Journal | 2012 Issue II Developing Rotterdam’s Skyline | 33 1930 1950 1970 1990 2010 façades (see Figure 3). Some examples of Visibility of Rotterdam’s tall building cluster 200m KPN toren brutalism were built as well during this time. The visual appearance of the city’s skyline is Space Tower The Delftse Poort (1992, 93 and 151 meters) determined by the size and the shape of the was the last design with mirrored glass area where a cluster of tall buildings is façades. These styles disappeared, and the Maastoren developing. To determine the grouping a building designs became more diverse. The 160m simple outline can be drawn that links the most prominent example of brutalism, the Delftse Poort outer buildings considered part of the cluster PTT Telecom building, a 51-meter tall tower (see Figure 4 and 5). If a new building is Erasmus bridge built in 1970, was demolished in 2007, erected within the outline it will not change 2nd wave removing it from the skyline altogether. the width of the city’s skyline, regardless of the 120m In a parallel development, foreign architects angle from which it is viewed. Any building Hoboken and internationally-operating Dutch architects erected outside the outline extends the became more involved in the design of tall skyline, as seen from a specific angle. buildings in Rotterdam. Until the mid-1990s, In the case of most buildings it is clear 1st wave tall buildings were predominantly designed 80m whether or not they belong to the cluster due by local architects, with the exception of SOM to their proximity to the other buildings. The and its three identical 95-meter tall Europoint current Rotterdam tall building policy building height towers built between 1975 and 1978. Since pre-wave assumes that tall buildings in the Central 50m then, international architects have played a year of completetion District, the Centre, the Nieuwe Werk and the major role in tall building design in Rotterdam. are part of one continuous area. white: residential or mixed-use high building The buildings designed by international black: non-residential high building The question remains if the tall buildings west dot: panorama/ or bridge pillar architects include Murphy Jahn’s Fortis Bank of this area, Park and Europoint, belong to the Figure 2. Scatter plots of the architectural height and the (1996, 104 meters), Renzo Piano’s Toren op year of completion of Rotterdam’s tall buildings, without area that makes up the visual skyline. From and with so-called tall building waves Zuid (2000, 96 meters), WZMH’s Millennium some angles these buildings west of the Tower (2000, 149 meters), Norman Foster’s center are visually part of the cluster and from World Port Centre (2001, 138 meters), other angles they are obviously not. Mecanoo’s (2005, 152 meters), KCAP’s Red Apple (2009: 128 meters), Alvaro A simple technique can be applied to visualize Siza’s (2010; 158 meters), OMA’s this. The area from which a building appears De Rotterdam (2013, 149 meters) and the list to be part of the cluster is determined by is growing. The presence of these drawing two lines that connect the building in international architects is particularly felt in question with the two buildings that mark the the design and construction of the tallest and borders of the cluster. If the angle between most prominent buildings in the tall building the two lines is larger than 90 degrees, then cluster. the area in which the building appears as part Figure 3. Rotterdam, Weena Boulevard. The architecture of the cluster dominates over the area in dominated by the use of mirrored glass façade. The Finally, there has been a marked difference in which it is visually separated from the cluster. Delftse Poort (1991) is on the left the use of tall buildings. Before 1990, the tallest buildings were office or university Based on this method, it appears that the periods before and after 1989–1992 display buildings. Many new tall buildings and buildings in the park area should be many qualitative differences relating to tall proposals are now planned for residential uses considered as part of the cluster: Hoboken building policy, architectural design, (Klerks 2005). Figure 2 illustrates this clearly. (1969, 112 meters) and the Euromast (1970, internationalization and the functional use of 185 meters). The three Europoint buildings are Looking at the scatter plot, there is an tall buildings. clearly not part of the Rotterdam tall building interesting lack of buildings between the cluster. Adjacent to the clusters of buildings In 1993, the Rotterdam Municipal Council 110- and 120-meter mark, and a slight drop above 120 meters, and between 80 and 120 launched its first tall buildings policy between 80 and 85 meters. Based on this meters, a large number of buildings were built (Hoogbouwbeleid) in a structured attempt to observation we have identified in earlier with heights ranging between 50 and 80 steer the development of tall buildings in the research three distinctive height categories in meters. All these buildings were reviewed to city (Dienst Stedenbouw + Volkshuisvesting Rotterdam (van der Hoeven 2004): assess whether they are part of the cluster. A 2000). The architectural quality of tall buildings a. above 120 meters; third outline is the result of this action. All from the era between 1969 and 1991 was b. between 80 and 120 meters; three outlines are displayed in the overall map. dominated by the use of mirrored glass c. below 80 meters.

34 | Developing Rotterdam’s Skyline CTBUH Journal | 2012 Issue II Central Central District District

Centre Centre

Erasmus MC Erasmus MC Europoint Europoint Nwe Eurasmus bridge Nwe Erasmus bridge Werk Werk

Park Park

Euromast Euromast Kop van Zuid Kop van Zuid

Figure 4. The 2015 multi-layered Rotterdam tall building cluster Figure 5. Map of the “official” Rotterdam tall building zones 2000–2010

True, the current tall building development impact of 130 tall buildings. In order to When examining tall buildings, the vertical within the overall cluster is driven by strategic analyze and represent the visibility of the tall size – specifically, the area of the façade – and projects such as the Rotterdam Central Station buildings in Rotterdam, a comprehensive weather conditions play a crucial role in area development and the Kop van Zuid GISc-based view shed method was applied prediction of probable visibility (Nicolai 1971). development. Standing within the cluster (Rød et al. 2009; Nijhuis 2009; Germino et al. To put it more precisely, the visual range of these two areas may appear as important 2001; and Nicolai 1971). The accuracy of this objects in the landscape depends on (Duntley sub-clusters. Looking from the outside analysis depends on the digital landscape 1948; Middleton 1952): however, it is almost impossible to visually model (DLM), and the rule for judging visibility a. the apparent contrast between the object separate them from the rest of the tall (Fisher 1991, 1993; Riggs and Dean 2007). and its background buildings, as illustrated by Figure 4. According to Riggs and Dean (2007), the b. the angles of the object The profile differs significantly from the tall average level of agreement which can be building zoning that ruled the development achieved is up to 85%. These findings suggest c. its shape and vertical area that it is better to express the analysis results of tall buildings between 2000 and 2010 (see d. the contrast threshold at the level of in terms of probability (Fisher 1995, 1996). Figure 5). That original tall building zoning was luminance (type of day) based on traditional urban design concepts However, to achieve the highest degree of e. the conditions and technique of observing such as building alignment, setback principle, reliability, an accurate barrier model, or digital boulevard and “visual axis.” But using the landscape model, was constructed consisting f. the eye level and related curvature of the visibility of the skyline as a means to identify of a digital elevation model (DEM) in earth (Duntley 1948) the cluster suggests that the city could allow combination with topographic data. The basis An important factor for determining the developments in a much wider area than is a high-resolution elevation model, the maximum visual range of distant objects is originally envisioned in the city’s guidance on Actueel Hoogtebestand Nederland (AHN-1, the meteorological optical range at different tall buildings. 1997–2003), which is precise to about 15 weather conditions. Observations from the centimeters per square meter. The location, Royal Netherlands Meteorological Institute architectural height and year of completion of (KNMI) show that the meteorological optical GISc-based Visibility Analysis the tall buildings were derived from the range by full daylight varies from nearly zero The visual impact of a single tall building was Emporis database (Emporis 2010) and added up to more than 10 kilometers (KNMI 2010). for the first time successfully reviewed to the digital topographic map. The resulting However, the average ranges of 12 kilometers (Lörzing et al. 2007; Lörzing 2011) in the case digital landscape model was corrected using (50% of the time), 20 kilometers (25%) and 28 of the 262-meter Belle van Zuylen tower, recent aerial photographs, field visits and kilometers (10%) are typical for Dutch proposed in 2007 near the Dutch city of street view imagery (Google Earth 2010). circumstances (Nijhuis 2012; Nicolai 1971). For Utrecht. The challenge faced in Rotterdam is A number of key parameters influenced the the analysis we calculated the maximum more complex. In question is the joint visual result of the GISc-based viewshed analysis. visual range of the tall buildings under 

CTBUH Journal | 2012 Issue II Developing Rotterdam’s Skyline | 35 different meteorological conditions by full Visibility buildings > 50 meters daylight and involved vertical area (length- Full daylight: meteorological optical range 20 km (25% of the time) in relation to vertical size and width proportion < 5), vertical shape area of the building (rectangular) and contrast value (object- background ≥ 2 %). The cumulative view sheds from the analysis show the probable visibility at a meteorological optical range of 20 kilometers and takes into account the curvature of the earth. At a distance of 10 to 20 kilometers the human eye has problems observing a group of buildings as separate objects. The buildings tend to blur into one. So far we have not able to adjust the analysis to incorporate this effect. The GISc-based visibility analysis results show two important aspects of visual information with regards to tall buildings: visual coverage and cumulative visibility (Nijhuis 2009). The output is meant to be descriptive rather than normative. Visual coverage is about where you can see tall buildings in the open landscape; the cumulative visibility is about how many tall buildings you can see. Or, to Figure 6. Visibility of all tall buildings in the municipality of Rotterdam put it differently, the results represent the intensity, or amount of tall buildings in the of these tall buildings, based on the outline of recognition requires sustained attention. skyline of the city. the tall building cluster and on the year of However, in reality this usually does not The visibility analysis of Rotterdam’s tall construction using 1970, 1992, and 2015 as happen. Attention is highly influenced by the building cluster reveals that their combined thresholds (see Figure 8). angles of the building, as well as how far away visual coverage reaches various places out of The results indicate that the visual coverage of it is, and how much it merges with the town at distances as far as 5 to 20 kilometers. tall buildings outside the city was more or less horizon. Within the city large bodies of open water, established in 1970. Extending the Euromast, A slight increase of visual coverage over the including the river, harbors and lakes, offer with the so-called Space Tower, to a height of years can be observed, especially north-west similar opportunities to see many tall 185 meters, contributes to this result. The and south-west of the Rotterdam buildings simultaneously. However, in most of cumulative visibility is getting “thicker” agglomeration, up to 1992 and onwards. the city the skyline cannot be seen. through the years. Tall buildings can be seen However, the dominance of the cityscape Discussions on the visual impact of tall from more places buildings should therefore make a careful inside the city, but distinction between the visual impact of the outside the city the 1970 skyline on the cityscape and the very different areas from where tall impact on the landscape. buildings can be seen does not seem to be Development of the Skyline growing. This implies that the 1970 skyline The accompanying maps show the visual of the Rotterdam coverage and effect of the tall buildings that cluster was dominated are currently considered part of the cluster at by individual and small vital moments in the development of the groups of singular tall Rotterdam skyline: 1970, 1992, and 2015. buildings. Landmarks Figure 6 shows the visual impact of all 130 are likely to be weak current and future buildings over 50 meters. references by The next graphic illustrates specific selections themselves. Their Figure 7. The Rotterdam cluster: visibility of the tall buildings built in 1970, 1992 & 2015

36 | Developing Rotterdam’s Skyline CTBUH Journal | 2012 Issue II dramatically increased over the years and is developments in a much wider area than KLERKS, J. 2005. ”New Metropolitan Living and the Skyscraper in a European City.” CTBUH Technical Paper. expressed by the increasing magnitude of originally envisioned in the city’s guidance on Accessed September 1, 2009. http://www.ctbuh.org. cumulative visibility of tall buildings. In recent tall buildings. The visual coverage of the KNMI. 2010. Daggegevens van het Weer in Nederland 1951 decades the cluster effect of tall buildings in buildings that make up the current Rotterdam t/m 2010. Metingenweerstation Schiphol: the skyline became the dominant factor in the tall building cluster is roughly equal to the Meteorologischzicht. De Bilt. visual impact. Starting north and south from coverage of the buildings that were already in LÖRZING, H., A. HARBERS, AND M. BREEDIJK. 2007. De Zichtbaarheid van de Belle van Zuylen-toren. 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