CTBUH Journal

Case Study: Trinity, Paris

Preparing High-Rises for Drones

Tall + Urban Innovation Trends of 2020

Chicago Code Changes: Structural Engineering Impacts

Double-Skin Façades for the Mediterranean Climate

CTBUH JournalInternational Journal on Tall Buildings and Urban Habitat

Tall buildings: design, construction, and operation | 2020 Issue II

Inside | 3CTBUH Journal | 2020 Issue II2 | CTBUH Journal | 2017 Issue xx

concept as skyline-building. It’s particularly prescient that this project is being constructed on an “infi ll” site in a development that was one of the classic tabula rasa urban-renewal, auto-oriented projects of the postwar period. This study in returning to principles of human scale, greenery, and pedestrian orientation puts a rather fi ne point on it by decking over an active highway.

If we are beginning to put the “Futurama” version of the future behind us, in which the private automobile began its largely successful campaign to remake society in its image, we have certainly not taken our eyes off the skies. What was, seemingly yesterday, only another near-future imaginary is now practically an inevitability—the presence of drones and vertical-takeoff -and-landing (VTOL) vehicles in urban airspace. In this issue we have prepared a triumvirate of articles to come to grips with the phenomenon. Debating Tall asks, “Are Drones Ready for Façade Inspection?” (see page 5); the intersection of fl ying vehicles and high-rises is explored in Talking Tall (see page 54), in a discussion with a “drone-forward” architect; and Ask a CTBUH Expert addresses the drone-skyscraper nexus from the thorny legal perspective (see page 58).

As I write this, the world is gripped with anxiety about what appears to be a pandemic, which threatens to disrupt the hyper-connected, seamless world we have been constructing. I am hopeful both that the medical profession swiftly prevails against the virus, and also, that we do not simply “return to business as usual” when the threat has passed. If the world has to push the “pause” button for a while, here’s hoping that when it resumes, we will have had some time to think about our impact on the planet and ourselves, and that we re-emerge with a renewed vigor to improve the building industry’s impact on both.

All the best,

Daniel Safarik, CTBUH Editor in Chief

At the risk of repeating myself, I can’t help but return to the signifi cance that has been attributed to 2020 as a milestone of a rapidly-advancing

“future,” which has—to my eyes—rather suddenly become the present. At the very least, it provides an opportunity to look back critically on the predictions we made in the foregoing years, and to present an honest accounting of how accurate we were. To that end, one of our research papers and our Tall Buildings in Numbers study in this issue (pages 44 and 52, respectively) examine the predictions CTBUH made in the fi rst Journal of 2012, as we appeared to be “Entering the Era of the Megatall.” At that time, some eight buildings of 600 meters’ or greater height were planned to have risen by 2020; in reality, there are only three. Our report and graphic study chronicle the trials and tribulations that got us to this point.

This is not to say that we have not made progress, however, for height alone is not the sole barometer of success in this industry, despite our predilection for keeping count. To that end, the common threads of technological innovation and humane design that run through the excellent projects in the 2020 CTBUH Awards program. We have chronicled these in the paper Tall + Urban Innovation 2020: Dominant Trends (see page 36).

It is equally, if not more important, to stay apprised of best practices in architecture and engineering, including the academic research that precedes common practice, and the codes that keep our projects safe and neighborly, which is why we have devoted space to papers such as Improving the Energy Effi ciency of a Mediterranean High-Rise Envelope (see page 20) and Chicago Building Code Modernization: Comparison of Prototype Building Designs (see page 28).

The dynamics of innovation and humane design are also converging in projects like Trinity in Paris (see Case Study, page 12), where site repair is as much a part of the

This Issue CTBUH Organizational Members members.ctbuh.org

2 | This Issue CTBUH Journal | 2020 Issue II

EditorDaniel Safarik, [email protected]

Associate EditorAntony Wood, CTBUH/IIT/Tongji University

Design & LayoutTansri Muliani, CTBUH

Board of TrusteesChair: Steve Watts, alinea Consulting, UKVice-Chair: David Malott, AI., USA Chief Executive O� cer: Antony Wood, CTBUH / Illinois Institute of Technology, USA / Tongji University, ChinaTreasurer: Charu Thapar, JLL, IndiaTrustee: Mounib Hammoud, Jeddah Economic Company, Saudi ArabiaTrustee: Abrar Sheriff , Turner International LLC, USATrustee: Kam Chuen (Vincent) Tse, WSP, ChinaTrustee: Shaofeng Wang, China State Construction Overseas Development Co., Ltd, China

CTBUH Expert Peer Review CommitteeAll papers published in the CTBUH Journal are peer-reviewed by an international panel of multi-disciplinary experts from within the CTBUH membership.

Published byThe Council on Tall Buildings and Urban Habitat© CTBUH 2020ISSN: 1946-1186

Council on Tall Buildings and Urban Habitat104 South Michigan Avenue, Suite 620 Chicago, IL 60603, USA

+1 312 283 [email protected] www.ctbuh.orgwww.skyscrapercenter.com

Copyright © 2020 Council on Tall Buildings and Urban Habitat. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, without permission in writing from the publisher.

Image CopyrightCTBUH Journal has endeavored to determine the copyright holders of all images. Those uncredited have been sourced from listed authors or from within CTBUH.

Print This Journal is printed by Lake County Press Inc., Chicago.

IndexingThe articles in the CTBUH Journal are indexed in the following databases:Avery Index to Architectural Periodicals CNKIEBSCOJSTORSCOPUS

Front cover: Trinity, Paris. © Laurent ZylbermanBack cover: Trinity, Paris—the terraces and suspended meeting rooms. © Hugo Hebrard

EID ArchitectureEnclos Corp.Envision Engineering ConsultantEpsteinFender KatsalidisFront Inc.HALFEN USA Inc.Hill InternationalHPP ArchitectsInvesta Property GroupJaeger Kahlen Partners ArchitectsJensen HughesJLLLarsen & ToubroLeMessurierLERA Consulting Structural EngineersLWK + PARTNERSMagnusson Klemencic AssociatesMcNAMARA • SALVIAMirvac GroupNishkian Menninger Consulting and Structural EngineersOJB Landscape ArchitectureOutokumpuPDW ArchitectsPei Cobb Freed & PartnersPermasteelisa GroupPickard Chilton ArchitectsPLP ArchitecturePNB Merdeka Ventures Sdn. BerhadPT. Gistama IntisemestaQuadrangle ArchitectsRambollRene Lagos EngineersRothoblaasSAMOO Architects and EngineersSchucoSeverud Associates Consulting EngineersShanghai Construction (Group) GeneralShenzhen Aube Architectural Engineering Design Co., LtdSika Services AGStudio GangSyska Hennessy GroupTata RealtyTAV ConstructionTongji Architectural Design GroupUNStudioV & A WaterfrontWalter P. Moore and AssociatesWATG UrbanWebber Design Pty LtdWebcor BuildersWillowWME Engineering ConsultantsWoods BagotYitian Design Group Co., Ltd.Zaha Hadid Architects

CONTRIBUTORSAkzoNobelAliaxisAlimakAllford Hall Monaghan MorrisAltitude Facade Access ConsultingAlvine EngineeringAMSYSCOAndrew Lee King Fun & Associates Architects Ltd.ArcelorMittalArchilier ArchitecturearchitectsAllianceArchitectural Design & Research Institute of Tsinghua UniversityArchitectusArmstrong Ceiling SolutionsArney Fender KatsalidisASHTROM GROUP LTDBarker Mohandas, LLCBenoybKL ArchitectureBoundary Layer Wind Tunnel LaboratoryBouygues Batiment InternationalBroad Sustainable Building Co.Broadway MalyanBrunkeberg SystemsCalatrava InternationalCanary Wharf GroupCanderel ManagementCareys Civil EngineeringCary Kopczynski & CompanyCB EngineersCCD / Cheng Chung DesignCCLCerami & Associates

Cermak Peterka PetersenChina Architecture Design & Research GroupChina State Construction Overseas Development Co., Ltd.Chongqing Jinke Design Research InstituteCivil & Structural Engineering Consultants (Pvt) Ltd.Code Consultants, Inc.Conrad GargettCosentini AssociatesCottee Parker ArchitectsCotter Consulting Inc.Cove Property GroupCox ArchitectureCoxGomylCraft Holdings LimitedCS Group Construction Specialties CompanyCSSC Complex Property Co.,LtdCubic ArchitectsDaewoo E&CDavy Sukamta & Partners Structural EngineersDCA ArchitectsDCI EngineersDecibel ArchitectureDeernsDIALOGDoka GmbHDong Yang Structural EngineersEGElenberg FraserElevating Studio Pte. Ltd.Enstruct Group Pty LtdEnvironmental Systems DesignEPEXYL S.A.Eric Parry ArchitectsFINE DNCFletcher Priest ArchitectsFM GlobalForster Engineering Consultants Co., Ltd.Foster + PartnersFXCollaborativeGal Nauer ArchitectsGEI ConsultantsGERB Vibration Control Systems (USA/Germany)GGLOGilsanz Murray Ste� cekGlobal Wind Technology ServicesGlumacgmp • Architekten von Gerkan, Marg und Partner GbRGoettsch PartnersGradient Wind Engineering Inc.Graziani + Corazza ArchitectsGrimshaw ArchitectsGuangdong JMA Aluminium Pro� le Factory (Group) Co., Ltd.Guangzhou Jianke Citiexpo Co.,LtdGuangzhou Yuexiu City Construction Jones Lang LaSalle Property Management Co., Ltd.Hariri Pontarini ArchitectsHASSELLHathaway DinwiddieHeller Manus ArchitectsHenning Larsen ArchitectsHilti AGHitachi, LtdHKA Elevator ConsultingHKS ArchitectsHOK Architects CorporationHousing and Development BoardHumphreys & Partners Architects, L.P.Hutchinson BuildersICD PropertyIDOM UK Ltd.Ingrid CloudInhabit GroupInternational Code CouncilInterpane GmbHIsraeli Association of Construction and Infrastructure EngineersJAHNJaros, Baum & BollesJotunJQZKEO International ConsultantsKHP Konig und Heunisch PlanungsgesellschaftKilla DesignKinemetrics Inc.KineticaKobi KarpKoltay FacadesKS Ingenieure ZT GmbHLCI Australia Pty Ltd.LCL Builds LimitedLendlease CorporationLiberty OneSteel

Longman LindseyM Moser AssociatesMaeda CorporationManntechMAURER SEMetal YapiMicroShade A/SMoelvenMori Building CompanyMoshe Tzur Architects Town PlannersMott MacDonald GroupMVRDVNabih Youssef & AssociatesNational Fire Protection AssociationNikken Sekkei, Ltd.Norman Disney & YoungNORR Group Consultants International LimitedO’Donnell & NaccaratoOLYMPIQUE Facade Access ConsultingOmraniaOrnamental Metal Institute of New YorkPalafox AssociatesPAN PartnersPavarini McGovernPeikkoPepper Construction CompanyPerkins and WillPlus ArchitecturePortman ArchitectsProcore TechnologiesPro� caR.G. Vanderweil EngineersRaftery CRE, LLCRAW DesignReal Estate Management (UK) LimitedRelated MidwestRhode PartnersRise Management Consulting LtdRJC EngineersRobert A.M. Stern ArchitectsRogers Stirk Harbour + PartnersRonald Lu & PartnersRonesans HoldingRoyal HaskoningDHVSafdie ArchitectsSanni, Ojo & PartnersSauerbruch Hutton Gesellschaft von ArchitektenSECURISTYLESETEC TPIShimizu CorporationSHoP ArchitectsSideriseSilverEdge Systems Software, Inc.Stanley D. Lindsey & AssociatesStantec Ltd.Steel Institute of New YorkStein Ltd.Steinberg HartStora Enso Wood Products Oy LtdStudco Australia Pty LtdSuperTEC Surface DesignSWA GroupSwinerton BuildersTaisei CorporationTakenaka CorporationTechnal Middle EastTengyuan Design Institute Co., LtdTerraconTetra TechThe Harman GroupThe Pakubuwono DevelopmentVetrocareVidaris, Inc.Voice Architecture LabVS-A GroupWerner Sobek GroupWeston Williamson + Partnerswh-p IngenieureWilkinsonEyreWOHA ArchitectsWTM Engineers InternationalWZMH ArchitectsY. A. Yashar Architects

PARTICIPANTS/ACADEMIC & MEDIA INSTITUTESThere are an additional 389 members of the Council at the Participant/Academic Institute/Media Institute level. Please seeonline for the full member list: members.ctbuh.org.

Supporting Contributors are those who contribute $10,000; Patrons: $6,000; Donors: $3,000; Contributors: $1,500; Participants: $750; Academic & Media Institutes: $500.

“ The significant electricity supply currently required to operate a vertiport may be an issue, and early engagement with electricity providers would be prudent to assess viability and cost.”

Humphreys, page 58

News and Events

This Issue Daniel Safarik, Editor-in-Chief

CTBUH Latest Antony Wood, Chief Executive Officer

Debating Tall Are Drones Ready for Façade Inspection?

Global News Highlights from the CTBUH Global News archive

02

04

05

06

Case Study

Trinity, Paris Jean-Luc Crochon

12

Research

Improving the Energy Efficiency of a Mediterranean High-Rise EnvelopeTanya Saroglou, Isaac Meir & Theodoros Theodosiou

Chicago Building Code Modernization:Comparison of Prototype Building DesignsJohn Viise, Matthew Cummins, Alberto Guarise & Daniel Koch

2020 Tall + Urban Innovation: Dominant TrendsCTBUH Staff

The Tallest 20 in 2020: Then and NowCTBUH Staff

20

28

36

44

Features

Tall Buildings in Numbers Evaluating 2012’s Predictions for the Tallest 20 in 2020

Talking Tall: Walter HughesHigh-Rise “Vertiports” and Other Near-Future Visions

Ask a CTBUH Expert: Emma Humphreys How to Make a Tall Building “Drone-Ready”?

52

54

58

CTBUH

59

60

62

63

Inside

20

28

44

CTBUH on the RoadCTBUH events around the world

Reviews Review of new books in the CTBUH Library

Meet the CTBUH Shonn Mills

CTBUH Organizational Member Listing

44 | CTBUH Research Report CTBUH Research Report | 45CTBUH Journal | 2020 Issue II CTBUH Journal | 2020 Issue II

In 2012, the CTBUH Journal published a research paper titled “Tallest 20 in 2020: Era of the Megatall—The Projected World’s Tallest 20 Skyscrapers in the Year 2020.” Though it was only eight years ago, the pace of change in the tall building world at the time was such that 2020 seemed like a distant lodestar in the future. The future, of course, has the inconvenient habit of appearing in the present far too early for the comfort of most. Today, the CTBUH Research and Editorial teams review the projections we made in 2012, the assumptions that guided them, and the roller-coaster reality of what has come hence.

Prediction 1 “By 2020, we can expect that at least eight megatall buildings (of 600 meters’ or greater height) will exist worldwide.”

Reality In the second quarter of 2020, there are three megatall buildings in existence. These are the Burj Khalifa, Dubai (828 meters); Shanghai Tower, Shanghai (632 meters); and Makkah Royal Clock Tower Hotel (601 meters), Mecca (CTBUH Skyscraper Center 2020).

What Happened? Five of the eight megatall buildings projected in 2012 to complete by 2020 did not achieve that goal. Here are their stories:

Wuhan Greenland Center, Wuhan • Predicted 2020 rank in 2012: 7 (606 m)• Actual rank in 2020: n/a (476 m)*

The Wuhan Greenland Center had been designed to rise to 606 meters with a curved

crown, but construction had already begun when aviation authorities then intervened, concerned that future flight paths around Tianhe International Airport would be curtailed if towers in the city rose to that height (see Figure 1). The compromise design, with a similar curved top but wider proportions, will rise to 476 meters, knocking Wuhan Greenland Center from a 2012–predicted number 7 rank in 2020 and out of “megatall” status. If completed today, the still under-construction building would be the world’s 23rd-tallest building.* It is currently difficult to predict a final completion date, however, due to the developer’s alleged failure to make payments to the contractor. In October 2019, the contractor removed all

The Tallest 20 in 2020: Then and Now

CTBUH Research Report

Abstract

This research paper undertakes a review of the 2012 report by the Council on Tall Buildings and Urban Habitat, “Tallest 20 in 2020: Entering the Era of the Megatall,” assessing the accuracy of the predictions made at that time against the reality of the present day. It reviews the development trajectory of CTBUH’s 2012 predicted and unanticipated 20 tallest buildings in the world in the year 2020, and places the results in regional, industry and historical context.

Keywords: Development, Economics, World’s Tallest Building

Figure 1. Wuhan Greenland Center, Wuhan, was intended to be a “megatall” at 606 meters (left) but was cut down by aviation authorities, to 476 meters (right). © AS+GG (left); Baycrest (cc by-sa) (right)

its workers from the site until the dispute could be settled (Sun 2019).

Jeddah Tower, Jeddah• Predicted 2020 rank in 2012: 1 (828 m)• Actual rank in 2020: n/a Jeddah Tower, which began construction in 2013 and was then called Kingdom Tower, has experienced numerous delays and remains under construction in 2020. News reports peg a “topping out” by the end of 2020, but it is unclear when completion may finally happen (Gibbon 2020). If it were completed now, and for some time in the foreseeable future, it would become the World’s Tallest Building at more than

Figure 2. Ping An Finance Center, Shenzhen–proposed in 2008 and originally set to rise 660 meters (left), it was completed in 2017 at 599 meters (right), due to changes in aviation restrictions. © Kohn Pedersen Fox Associates (let); Tim Griffith (right)

1,000 meters (the exact height figure remains undisclosed).

Seoul Light DMC Tower, Seoul• Predicted 2020 rank in 2012: 4 (640 m)• Actual rank in 2020: n/a The predicted world’s fourth-tallest building in 2020 was expected to reach 640 meters. In 2012, the contractor that had intended to construct the building failed to pay for the land plot, and the project was scrapped (Bae 2015). Discussions have been ongoing since 2015 to restart the project, potentially with a shorter tower (Kim 2018).

Signature Tower, Jakarta• Predicted 2020 rank in 2012: 4 (638 m)• Actual rank in 2020: n/a* The Signature Tower in Jakarta, proposed in 2009, at 638 meters, was anticipated in 2012 to become the world’s fifth-tallest building by 2020. However, multiple design changes and failed geotechnical/hydrological tests caused the first round of delays (Alexander 2014). The project eventually received design approval from local authorities in 2015, and approval for construction in 2017 (Alexander 2015a, 2015b; Freycinetia & Puspa 2017). However, it was still short some US$1.7 billion in funding, and remains stalled (Dwijayanto 2018).

This is not to imply that the road had been smooth for the three megatalls that did complete, however—or for that matter, for practically any of the buildings on the 2020 World’s Tallest List, then or now.

Burj Khalifa, Dubai• Predicted 2020 rank in 2012: 2 (828 m)• Actual rank in 2020: 1 (828 m) The Burj Khalifa, completed in 2010, became the World’s Tallest Building at that time and retains the title today. Its iconic status has driven much development around its periphery, delivering value above and beyond the building itself. Its grand opening was in January 2010, which coincided with a name change from “Burj Dubai” after Sheik

Khalifa bin Zayed al-Nahyan provided financial assistance to finish the project (Thomas 2010). It was declared the World’s Tallest Building by the Council in March 2010 (CTBUH 2010).

Ping An Finance Center, Shenzhen• Predicted 2020 rank in 2012: 3 (660 m)• Actual rank in 2020: 4 (599 m) Like its cousin in Wuhan, Ping An Finance Center received a “haircut” due to aviation restrictions being imposed after the buildings had been designed. The office building was originally intended to reach 660 meters by way of a spire at its top (see Figure 2). During the design process, local aviation authorities, concerned that a building of that height might impede the range of potential flight paths in and out of

Shenzhen Bao’an International Airport, restricted its height to 600 meters, maximum. The redesign completed the building’s architectural expression with a pyramidal crown, bringing its final height to 599 meters—and thus removing the classification of “megatall.”

Shanghai Tower, Shanghai• Predicted 2020 rank in 2012: 6 (632 m)• Actual rank in 2020: 2 (632 m) While Shanghai Tower didn’t break ground until 29 November 2008, plans for a tower on the Lujiazui financial district site emerged as early as 1993, with a group of three towers; Jin Mao Tower (1999) and Shanghai World Financial Center (SWFC) (2008) comprising the two “sisters” of a “three sisters” tower plan. Shanghai Tower completed in 2015, but had

* Buildings must be fully clad and ready for occupancy in order to qualify as “complete” by CTBUH criteria, and to be officially entered into height rankings.

Journal2020_IssueII.indd 44-45 3/11/2020 2:18:32 PM

28 | Codes and Regulations Codes and Regulations | 29CTBUH Journal | 2020 Issue II CTBUH Journal | 2020 Issue II

Chicago Building Code Modernization: Comparison of Prototype Building Designs

Codes and Regulations

Background

For many years, local design and construction industries understood there was a need to better align Chicago’s Building Code (CBC) with more modern codes and standards used throughout the US. Through collaboration with many departments within the City of Chicago, the Mayor’s Office, and more than 150 volunteer technical experts and industry leaders, the Chicago Building Code was comprehensively revised in 2019. The revised structural requirements are based upon the International Building Code (IBC)—the modern national standard, while maintaining and introducing special Chicago-specific provisions.

As part of the new code adoption process, projects filed between 1 December 2019 and 1 August 2020 will have the option of using a design methodology based on the original (pre-2019) CBC or the new 2019 CBC, which references the 2018 IBC. After 1 August 2020, all new designs submitted for approval will need to conform to the new 2019 CBC.

Study Objective and Scope

Structural engineers familiar with the CBC and IBC recognize that design lateral forces developed by the two codes can vary significantly. Low-rise buildings may realize a reduction in wind loads with the IBC, but as a

Abstract

This research paper, an abridged version of a white paper produced by the Chicago Chapter of the Council on Tall Buildings and Urban Habitat (CTBUH), reviews the potential impact of changes to the city’s building code as it is adapted to the International Building Code standard. Its main objective is to uncover the effect of IBC loading standards on the structural designs of a range of taller buildings in Chicago that may utilize prescriptive code design methodology, to assess the cost implications of a change in loading standards, and to assess the effect of IBC’s seismic loading requirements on representative local building projects.

Keywords: Chicago Building Code, International Building Code, Structural Engineering, Tall Buildings

building gets taller and the exposure category increases (as specified by ASCE 7 Exposure Category B to D), wind loads can significantly increase. Additionally, the IBC requires that designs consider seismic loading, so heavier low-rise buildings may also see an increase in demand from new code loading.

The study presented in this paper attempts to answer the following questions:

• How does the IBC loading affect the structural designs of a range of taller buildings in Chicago that may utilize prescriptive code design methodology?

• How significant is the impact to structural cost?

• How does seismic loading impact these sample building designs?

In order to gain insight into these questions, three prototype buildings were analyzed and designed according to both CBC and IBC. The prototype buildings considered do not represent the full range of Chicago’s building stock, but are representative of the building types that are less than 400 feet (122 meters) tall, and as a result can utilize prescriptive code provisions for design (i.e., no wind tunnel testing). Additionally, a low-rise reinforced concrete office building is also considered for study, since short and heavier buildings are more susceptible to seismic loading. Figure 1. Isometric view of the prototype buildings.

The three prototype buildings examined as part of this research paper are shown in figures 1 and 2 and a detailed description of each is provided below.

Prototype Building 1

Prototype Building 1 is a residential tower with a 15-foot, 8-inch (4.8-meter) ground floor lobby and 36 floors at a 10-foot, 8-inch (3.3-meter) floor-to-floor height. The building roof has an elevation of 399 feet, 8 inches (121.8 meters) (see Figure 1), just below the 400-foot (121.9-meter) threshold requirement for wind tunnel testing per IBC.

The floor plate is 100 feet (30.5 meters) square, with columns around the perimeter spaced at 30 feet (9.1 meters) on center (see Figure 2). Elevated floors are 8-inch- (203-millimeter)-thick post-tensioned concrete slabs. The lateral system consists of a concrete bearing shear wall core with dimensions of 44 feet, 9 inches (13.6 meters) and 30 feet (9.1 meters). The core has web walls at the elevator and stairs that are 10 inches (254 millimeters) thick and are included in the analysis model. Concrete link beams at the core wall door rough openings are 29 inches (737 millimeters) deep and match the thickness of the shear walls. This corresponds to a door opening height of 8 feet, 3 inches (2,514 millimeters). Widths used for the door rough openings are 4 feet (1,219 millimeters) for single doors, and 8 feet (2,438 millimeters) for double doors.


Prototype Building 2 is an office building with a 20-foot (6.1-meter) ground floor lobby and 19 floors at a 14-foot (4.3-meter) floor-to-floor height. The building roof has an elevation of 286 feet (87.2 meters) (see Figure 1). An exterior windscreen extends an additional 14 feet (4.3 meters) forming a mechanical penthouse for a total building height of 300 feet (91.4 meters) above grade.

The floor plate is 180 feet by 130 feet (54.9 meters by 39.6 meters). Columns are spaced

on a 30-foot (9.1-meter) grid in the longitudinal direction with 45-foot (13.7-meter) lease spans on each side of an interior 40-foot (12.2-meter) bay (see Figure 2). The floor system consists of 3-1/4-inch (83-millimeter) lightweight concrete on a 3-inch (76.20-millimeter) metal deck supported by structural steel infill framing at 15 feet (4.6 meters) on center. The lateral system consists of a concrete bearing shear-wall two-bay core, centered in the building with overall dimensions of 60 by 40 feet (18.3 by 12.2 meters). Concrete link beams at the core wall door openings are 36

Matthew Cummins

Daniel Koch

Authors

John Viise, Managing Principal Matthew Cummins, Project Engineer Alberto Guarise, Senior Project Engineer Daniel Koch, Project Engineer DeSimone Consulting Engineers 150 North Wacker Drive, Suite 2660 Chicago IL 60606 United States t: +1 312 493 4100 e: [email protected] de-simone.com

John Viise is the Managing Principal of DeSimone’s Chicago office. For over 25 years, Viise has been providing structural services for high-rise and special-use structures throughout the world. He is at the forefront of technical design, through active participation in industry research and knowledge sharing. Matthew Cummins currently serves as a Project Engineer in DeSimone’s Chicago office where he actively supports the firms Structural Engineering and Forensics practices. Cummins has over seven years of experience in structural analysis, design, detailing and construction administration on numerous new building and retrofit projects. Alberto Guarise currently serves as a Senior Project Engineer in DeSimone’s Chicago office. Guarise has over eight years of experience providing design and construction phase services in two major metropolitan areas: New York and Chicago, including high-rise and medium-rise office, residential developments, and sports arenas. Daniel Koch currently serves as a Project Engineer in DeSimone’s Chicago office where he actively supports the firms Structural Engineering and Forensics practices. His project experience includes: commercial, education, energy, and government facilities design.

John Viise

Alberto Guarise

Prototype 1

37-story Residential Tower 400 feet (121.9 meters) tall 100 x 100 feet (30.5 x 30.5 meters)

Prototype 2

20-story Office Building 286 feet (87.2 meters) tall 180 x 130 feet (54.9 x 39.6 meters)

Prototype 3


inches (914 millimeters) deep and match the thickness of the shear walls. This corresponds to a door rough opening height of 11 feet (3,353 millimeters). Widths used for the door rough openings are 8 feet (2,438 millimeters).


Prototype Building 3 is an office building with a 20-foot- (6.1-meter)-high ground floor lobby and 9 floors at a 14-foot (4.3-meter) floor-to-floor height. The building roof has an elevation of 146 feet (44.5 meters) (see Figure 1).

“The Chicago Wind Climate model suggests that wind loading from the easterly winds is expected to be significantly lower than prevailing strong winds from south and west.”

20 | Façades Façades | 21CTBUH Journal | 2020 Issue II CTBUH Journal | 2020 Issue II

Introduction

Although the potential of tall buildings to improve the overall sustainability of urban life is strong, further research and experimentation is needed, in order for this typology to comply with current and near-future regulations on embodied carbon and carbon emissions (EU 2010; Voss, Musall & Lichtme 2011; NYC 2015). Additionally, there is a significant gap between the practice of high-rise development worldwide, and the expertise gained on how to make these buildings more sustainable and energy-efficient (Donnolo, Galatro & Janes 2014; Simmonds 2015).

Tel Aviv, Israel, the focus of this study, has experienced vibrant high-rise activity. In 2011, the city’s Planning and Construction Committee issued the 2025 City Master Plan, setting new guidelines allowing further skyrise development (Fox 2011) (see Figure 1). This study considers high-rise buildings as an urban phenomenon closely related to city living, and studies design strategies for advancing their energy efficiency.

An important consideration of high-rise buildings is their vast scale, which is also

Abstract

This study focuses on the building envelope as the mediator between interior and exterior climatic conditions, examining its influence on energy loads. The parameters are: climatic conditions of the building’s location (Mediterranean climate), the thermal properties of the building envelope, and the effect of building height, on a high-rise office building with increased internal heat gains. The proposed envelope under study is a glazed curtain wall design, reflecting current high-rise architectural tendencies. Simulation results are in favour of a double-skin envelope design, with double low-e glazing as the exterior layer, and single-layer clear glazing on the interior, with two exterior windows that open and close in relation to building height, exterior environmental conditions and interior thermal comfort. The outcome is a dynamic building envelope that adapts and performs in relation to the above parameters.

Keywords: Climatic Response, Envelope, High-Rise, Mediterranean Climate, Thermal Performance

translated into increased energy loads, in comparison with low-rise construction (Cook, Browning & Garvin 2013; Leung & Ray 2013). As a result, their impact on the urban scale is much more energy-intensive than all other construction. According to the United Nations Environmental Program - Sustainable Buildings and Climate Initiative (UNEP-SBCI), the emissions produced from the operational energy (OE) of buildings, mainly used for heating, cooling and lighting, form the largest source of building-related greenhouse gas (GHG) emissions (approximately 80–90 percent), in relation to the emissions produced by the embodied energy (EE), used in the process of raw material extraction and processing (La Roche 2012). In addition, the building sector today is the most energy-intensive sector, accounting for almost 50 percent of GHG emissions. So, in order to reduce these, it becomes crucial to enhance the energy efficiency of buildings by reducing the OE.

This study looks at improving the energy efficiency of high-rise buildings, by focusing on the initial concept design stages, and more specifically on the design of the building envelope, considered as a passive design strategy that has the potential of

Improving the Energy Efficiency Of a Mediterranean High-Rise Envelope

Façades

Authors

Tanya Saroglou, Post-Doctorate Researcher Isaac A. Meir, Professor Structural Engineering Department Jacob Blaustein Institute for Desert Research Ben-Gurion University of the Negev Sede Boqer Campus Midreshet Ben-Gurion 84990, Israel t: +972 5 0252 3674; f: +972.8.6596881 e: [email protected] in.bgu.ac.il Theodoros Theodosiou, Associate Professor Laboratory of Building Construction & Building Physics, School of Civil Engineering Aristotle University of Thessaloniki Building E10, University Campus 54124 Thessaloniki, Greece t: +30 2310 995 818 e: [email protected] auth.gr/en/civil

Tanya Saroglou, PhD is a qualified architect in the UK (ARB) and Greece (TEE), with experience in architectural design and project management. In 2003 she completed her diploma in architecture at Kingston University. In 2006, she was awarded the Professional Practice and Management in Architecture from the Bartlett, University College London, and in 2013 an MSc in Sustainable Design from the University of Edinburgh. She has just completed her PhD studies at Ben-Gurion in Israel, via a thesis titled: “Design Strategies Towards More Energy-Efficient High-Rise Buildings,” and continues the research as a post-doctorate student. Her research so far has yielded three Q1 peer reviewed papers, and four papers published in peer-reviewed conference proceedings. Isaac A. Meir, PhD is affiliated with the Desert Architecture & Urban Planning Unit (since 1986), and Structural Engineering Department, Faculty of Engineering Sciences (since 2018) at Ben-Gurion University. Meir participates in the design of environmentally conscious, experimental projects in deserts. He is a consultant to Israel’s ministries of Construction and Housing, Energy, Water and Infrastructures, the Israel Land Administration, and the Standards Institute of Israel. Meir heads multidisciplinary teams focusing on green technologies and sustainable development. Research interests include sustainable design in arid zones; post-occupancy evaluation; indoor environment quality; life cycle energy analysis; zero-energy settlements; energy and tall buildings. He is the recipient of the Israel Green Building Council Award for Leadership in Green Building (2016). Theodore Theodosiou, PhD is an associate professor at the Laboratory of Building Construction & Building Physics in the Civil Engineering Department of the Aristotle University of Thessaloniki. His research interests include building energy efficiency, building physics, energy simulation of buildings, low-, passive- and near-zero-energy buildings. He has participated in various research programs, more than 80 national and international conferences, published chapters in scientific books, has published 35 papers in peer-reviewed scientific journals with more than 870 references.

reducing energy loads, by acting as a mediator between indoor and outdoor conditions (Cheung, Fuller & Luther 2005; Saroglou et al. 2017). A vital consideration in this relationship is the climatic conditions of the building’s location. So, by designing a climatically responsive building envelope that interacts appropriately with the ambient climatic conditions, it is possible to take advantage of passive heating and cooling techniques, and reduce the operational energy, i.e., heating and cooling (Yik 2005; Choi, Cho & Kim 2012).

However, current architectural tendencies, initiated from the mid-20th century onwards, especially prominent in high-rise buildings, portray an increased transparency of the envelope, and lightness of the structure, resulting in high cooling and heating energy loads (Allard & Santamouris 1998). On the other hand, during the last few years, double-skin façades (DSFs) have gained popularity over single-skin curtain walls, as a more advanced envelope scenario that leads to improvements of the building’s energy performance (Wood & Salib 2013). But, despite the number of built DSF built projects, and the numbers of DSF studies conducted, design guidelines on DSF energy performance are lacking, especially in relation to local climate (Joe et al. 2014; Ahmed et al. 2015; Ghaffarianhoseini et al. 2016).

This paper studies the performance of a building envelope for a high-rise reference model at different heights, in the hot and humid climate of Tel Aviv. The Tel Aviv climate (in terms of dry-bulb temperature, relative humidity, wind speed, and wind direction) is shown in Figure 2. Heating and cooling load comparisons are made by gradually upgrading the thermal properties of the building envelope for improving energy efficiency. Studies in hot climates are of special importance, due to the increased solar gains entering a glass façade, intensifying the cooling requirements. In addition, most research on double-skin envelopes, the focus of this study, has predominantly been undertaken in cold and temperate climates, with limited research

taking place in hot ones (Hamza 2008; Pomponi et al. 2016; Halawa et al. 2018).

Design Considerations for High-Rise Energy Efficiency

The Effect of Height on High-Rise Energy Loads A building interacts with the outdoors through the envelope (walls, roof, windows) generally, and specifically with the thermal properties of the materials that make up the building envelope. When estimating the energy loads of a high-rise building, it becomes important to take into consideration the changing microclimate with height, and how this affects the materials of the building envelope, through heat exchange with the ambient air by

Figure 1. Tel Aviv skyline. © Antony Wood

Relative Humidity (%)

Wind Direction (deg)

Global Solar Radiation Rate per Area (W/m2)

Dry-bulb Temperature (ºC)

Wind Speed (m/s)

ºCm/s

Months of the Year

W/m2

%450

400

350

300

250

200

150

100

50

0

30

25

20

15

10

5

00 1 2 3 4 5 6 7 8 9 10 11 12





Wind Speed (m/s)

ºCm/s

Months of the Year

W/m2

%450

400

350

300

250

200

150

100

50

0

30

25

20

15

10

5

00 1 2 3 4 5 6 7 8 9 10 11 12

Figure 2. Tel Aviv annual climatic data. Source: EnergyPlus

Journal2020_IssueII.indd 20-21 3/11/2020 2:13:59 PM

6 | Global News CTBUH Journal | 2020 Issue II

Visit the daily-updated online resource for all the latest news on tall buildings, urban development, and sustainable construction from around the world at: ctbuh.org/news

Liberty Market Tower, Toronto. © Lifetime Developments / Mel Pearl

Global News

Americas

An investment from the Canadian federal government will support an affordable housing component with CA$130 million (US$99 million) in downtown London, Ontario. Consisting of two residential buildings at 495 Talbot Street and 110 Fullarton Street, the development is slated to designate a quarter of its 420 units toward affordable housing.

In Toronto’s Liberty Village, a 16-year-long redevelopment project draws to a close with the launch of the 28-story, mixed-use Liberty Market Tower. The building will complete the Liberty Market Complex, which includes the Liberty Market Building and Liberty Market Lofts.

Further down the lakefront from Toronto, Mississauga is set to be the site of a massive, 37-tower megaproject, called The Square One District, which just received phase-one approval and will unfold over multiple decades. The development is planned to host 18,000 residential units, as well as office, retail, and entertainment space over its 1.6 million square meters of programming.

In the always-busy New York City, the cantilevered, glass-clad H Hotel W39 is progressing, with an estimated delivery date of 2021. The 65-room hotel is rising from a narrow plot below Bryant Park, and will eventually top out at 132 meters. Uptown, a proposed hospital tower redevelopment, the Lenox Hill Hospital Complex, has gone through a change to its design, which may include amending or eliminating the 41-story residential tower that was to accompany the hospital campus.

A permit has been filed for a high-rise tower to replace a parking garage on Boston’s waterfront. The Pinnacle at Central Wharf would be a 42-story, 182-meter tower, with a mix of retail and dining, offices, and residential programs, according to plans.

Along Chicago’s popular lakefront, a creative plan was unveiled to bring 500 units to a corner site just west of the city’s Lake Shore Drive. The proposed project, 640 West Irving Park Road, would convert the multi-building campus of a former high school into 275 residential units. A 23-story tower, which would replace the existing parking lot, would add 220 senior living, assisted living, and

memory care units. In Detroit, the David Stott Building, an Art Deco skyscraper, has been fully renovated. Purchased in 2015 for US$14.9 million, it had been undergoing renovations for the past several years, which included replacing windows, terra cotta and approximately 60,000 bricks on its exterior. Despite two delays, Lakeview Tower, a 15-story residential building, is slated for Duluth’s downtown, delivering 204 apartments and commercial space on the ground floor. Construction is expected to start in the winter of 2020.

Over on the United States’ West Coast, the Planning Commission in San Francisco has approved a new 61-story, 246-meter mixed-use tower at Transbay Center. Located at 542–550 Howard Street, the high-rise is anticipated to potentially be the last significant tower in the Transbay district. Further south in Los Angeles, Park Fifth, a 24-story high-rise building, along with a seven-story mid-rise building called Trademark, have reached completion in the city’s downtown. Park Fifth offers 347 apartments, as well as a 360-degree-view rooftop deck, an infinity pool, and other amenities. It is located near the Pershing

Park Fifth, Los Angeles. © MacFarlane Partners

http://www.ctbuh.org/news/

Global News | 7CTBUH Journal | 2020 Issue II

Toranomon Hills Business Tower, Tokyo. © Mori Building Co., Ltd. Kokusai Akasaka Building, Tokyo. © Terri Meyer Boake

Square Metro Station, in order to increase commuter convenience.

In Atlanta, a 46-story mixed-use tower is set to rise, potentially up to 168 meters, at 1138 Peachtree Street. If completed, the tower would feature 317 luxury apartments, as well as 3,000 square meters of retail space, and a nine-story parking deck.

In Charlotte, North Carolina, 700–722 North Smith Street is a 37-story residential tower coming to the fast-growing city. The project has been permitted to have up to 603 square meters of commercial space and 350 condo or apartment units on the site.

A site in the Symphony Park District of Las Vegas could host a 20-story residential tower by 2024. The City Council granted approval to the project’s developer to proceed with building 400 units in the downtown area at 600–798 West Symphony Park Avenue.

In another metro region with a growing high-rise living market, Frisco, Texas, part of the Dallas–Fort Worth metroplex, the new 19-hectare Gate development will contain Gate Tower with a 231-room luxury hotel

and a 90-residence apartment component, slated for a 2024 opening.

Two residential complexes are making headway in Guatemala City. Parque Mateo, a planned three-tower complex, is part of a revitalization of the city’s Zone 7, and will deliver a total of 450 apartments in two-bedroom and three-bedroom configurations. The four towers that comprise Céntrico, a complex in the city’s Zone 5, will each reach 14 stories, and contain 497 apartments total between them. Construction will consist of four phases, with each one focusing on the completion of a tower. The project’s aesthetic was inspired by Europe’s urban landscape. In Zone 4, Granat, a mixed-use, 16-story building is topped out, and set for a completion in 2020. The tower, which features greenery on its exterior, has two commercial levels, four levels of offices, one boutique hotel story, and nine stories of apartments.

An environmental impact study was submitted to the Panama Ministry of Environment for a planned development in the San Francisco district of Panama City. The two-tower, mixed-use complex, called Le Parc Residences, will have commercial

“Miracles and dreams can become real.”

Helmut Jahn, Principal, JAHN. Letter to Illinois Governor J.B. Pritzker to

save the Thompson Center, Chicago, from demolition.

THEY SAID

space and 288 apartments. In San José, Costa Rica, the second tower in the Azenza Towers residential complex has commenced construction. It will be the same height as the existing tower in the complex: 23 stories and 78 meters.

Asia & Oceania

In Tokyo, projects continue apace, as Toranomon Hills Business Tower wraps up construction. The 36-story tower is part of the mixed-use Global Business Hub at Toranomon Hills Complex, which is planned to deliver five towers, some exceeding 50 stories. Over in Asakusa, a 1970s Tokyo icon, the 26-story Kokusai Akasaka Building is to

12 | Case Study: Trinity, Paris CTBUH Journal | 2020 Issue II

Bridging Communities, Building Serendipity

Case Study: Trinity, Paris

Introduction

In 2019, Paris’ La Défense ranked fourth among the most attractive business districts worldwide, after the City of London, Midtown New York, and Marunouchi in Tokyo (Lhermitte et al. 2017). Built on an artificial slab 60 years ago on the western edge of Paris, La Défense, which had once benefited from cheap land, must today reinvent its model. Originally designed to vertically

Author

Jean-Luc Crochon, Partner Cro&Co Architecture 13 rue Gracieuse 75005 Paris France t: +33 1 5543 3131 e: [email protected] croandco.archi

Jean-Luc Crochon was born in Paris, where he also graduated from the École Nationale Supérieure des Beaux-Arts. He quickly founded his own agency, whilst also working as consultant architect for RFR Peter Rice. In 1998, he created a joint agency with Cuno Brullmann. For over six years, they worked on high-prestige projects, such as the restructuring of the Centre of New Industries and Technologies (CNIT) at La Défense, and the extension of the hospital Foch in Suresnes. The agency continues its development on different projects, research buildings, housing, offices and academic buildings. In 2018 Crochon set up CroMe Studio, another architecture studio dedicated to international projects, with Nayla Mecattaf. Crochon is a member of the Board of Directors of the Architecture et Maîtres d’Ouvrage (AMO) and a member of the Architectes Français à L’Export (AFEX).

separate pedestrian from vehicular flows, so as to create a more functional city, inspired by Le Corbusier’s Plan Voisin, La Défense has overcome and reconstituted the morphological constraint of its raised plinth, which once made it difficult for users to understand and navigate (see Figure 1).

It has been a goal of the developer to make La Défense more urbane and more human-scaled. Over the last 10 years, several projects have been launched to sew the circular boulevard around the La Défense slab more tightly together, creating a real urban continuity that extends beyond La Grande Arche, reinventing the office park, and especially, infusing the district with new uses.

Jean-Luc Crochon

Abstract

The Trinity tower, located in the Paris La Défense business district, is a 32-story, 140-meter tower, whose most outstanding feature is its construction upon a concrete slab, which itself is suspended above a seven-lane road, a first in France. A major feat of civil engineering, the slab is planted, providing 3,500 square meters of landscaped public space, linking the previously disconnected neighborhoods of the CNIT (National Center of Industries and Techniques) and Coupole-Regnault: a concrete solution for enhancing the quality of life of its users on an urban scale. Furthermore, Trinity is La Défense’s first tower to develop an offset core, yielding a “heart of life,” with exterior glass-walled elevators running along the façade. Diverging from the traditional office building format, Trinity is a tower conceived to facilitate open interaction with its environment, and promotes a new way of working.

Keywords: High-Rise, Office, Urban Design, Social Engineering, Structural Engineering

Figure 1. Site plan showing the location of Trinity Tower and its immediate neighbors.

ab

d

e

f

gh

i

j

c

a Centre of New Industries and Technologies (CNIT)b Grande Arche de la Défensec La Défense Metro Stationd Les Quatre Temps Department Storee Notre-Dame de Pentecôte Churchf Tour Arevag Tour Total Coupoleh Trinityi Tour Sequoiaj Avenue de la Division Leclerc

ab

d

e

f

gh

i

j

c

a Centre of New Industries and Technologies (CNIT)b Grande Arche de la Défensec La Défense Metro Stationd Les Quatre Temps Department Storee Notre-Dame de Pentecôte Churchf Tour Arevag Tour Total Coupoleh Trinityi Tour Sequoiaj Avenue de la Division Leclerc

Case Study: Trinity, Paris | 13CTBUH Journal | 2020 Issue II

Figure 2. Trinity was a significant site-repair project, resolving grade changes for pedestrians and bridging over an active highway. © Laurent Zylberman

At the base of the new, ultra-modern office towers are restaurants, bars, shops and public spaces that have the potential to transform La Défense into a 24-hour-a-day district, a destination for white-collar workers and all Parisians, on weekdays but also on weekends.

If it is to become more urban and claim its rightful place as a desirable destination in “Le Grand Paris,” La Défense must not lose sight of its goal to become the top European business center. Its particularly low office vacancy rate reflects the dynamism of the French business center.

Trinity was designed as a comprehensive and contextual urban project for La Défense (see Figure 2). In order to successfully integrate into an atypical site, it combines three major axes in a single construction program: the erection of a building, the creation of major urban link, and a large-scale intervention to enclose highways. In other words, Trinity is at once a work of architecture and urbanism, with public benefits.

An Urban Project

Trinity was designed for a narrow site and a need to span a highway, but also for its immediate surroundings, which include several architectural icons: the CNIT and Tour Areva, smaller buildings such as Notre-Dame de la Pentecôte Church, and residential buildings. The tower was sculpted to slip into this dense urban context, keeping a 27-meter minimum distance from Tour Areva, while conserving views and perspectives for its neighbors, notably between Tour Total Coupole and the CNIT. Continuous exchange with the neighborhood via public consultation meetings throughout development enabled the project to mature and meet residents’ expectations.

The concrete slab built over the highway provides real solutions for creating urban connections and enhancing the quality of

20 | Façades CTBUH Journal | 2020 Issue II

Introduction

Although the potential of tall buildings to improve the overall sustainability of urban life is strong, further research and experimentation is needed, in order for this typology to comply with current and near-future regulations on embodied carbon and carbon emissions (EU 2010; Voss, Musall & Lichtme 2011; NYC 2015). Additionally, there is a significant gap between the practice of high-rise development worldwide, and the expertise gained on how to make these buildings more sustainable and energy-efficient (Donnolo, Galatro & Janes 2014; Simmonds 2015).

Tel Aviv, Israel, the focus of this study, has experienced vibrant high-rise activity. In 2011, the city’s Planning and Construction Committee issued the 2025 City Master Plan, setting new guidelines allowing further skyrise development (Fox 2011) (see Figure 1). This study considers high-rise buildings as an urban phenomenon closely related to city living, and studies design strategies for advancing their energy efficiency.

An important consideration of high-rise buildings is their vast scale, which is also

Abstract

This study focuses on the building envelope as the mediator between interior and exterior climatic conditions, examining its influence on energy loads. The parameters are: climatic conditions of the building’s location (Mediterranean climate), the thermal properties of the building envelope, and the effect of building height, on a high-rise office building with increased internal heat gains. The proposed envelope under study is a glazed curtain wall design, reflecting current high-rise architectural tendencies. Simulation results are in favour of a double-skin envelope design, with double low-e glazing as the exterior layer, and single-layer clear glazing on the interior, with two exterior windows that open and close in relation to building height, exterior environmental conditions and interior thermal comfort. The outcome is a dynamic building envelope that adapts and performs in relation to the above parameters.

Keywords: Climatic Response, Envelope, High-Rise, Mediterranean Climate, Thermal Performance

translated into increased energy loads, in comparison with low-rise construction (Cook, Browning & Garvin 2013; Leung & Ray 2013). As a result, their impact on the urban scale is much more energy-intensive than all other construction. According to the United Nations Environmental Program - Sustainable Buildings and Climate Initiative (UNEP-SBCI), the emissions produced from the operational energy (OE) of buildings, mainly used for heating, cooling and lighting, form the largest source of building-related greenhouse gas (GHG) emissions (approximately 80–90 percent), in relation to the emissions produced by the embodied energy (EE), used in the process of raw material extraction and processing (La Roche 2012). In addition, the building sector today is the most energy-intensive sector, accounting for almost 50 percent of GHG emissions. So, in order to reduce these, it becomes crucial to enhance the energy efficiency of buildings by reducing the OE.

This study looks at improving the energy efficiency of high-rise buildings, by focusing on the initial concept design stages, and more specifically on the design of the building envelope, considered as a passive design strategy that has the potential of

Improving the Energy Efficiency of aMediterranean High-Rise Envelope

Façades

Authors

Tanya Saroglou, Post-Doctorate Researcher Isaac A. Meir, Professor Structural Engineering Department Jacob Blaustein Institute for Desert Research Ben-Gurion University of the Negev Sede Boqer Campus Midreshet Ben-Gurion 84990, Israel t: +972 5 0252 3674; f: +972.8.6596881 e: [email protected] in.bgu.ac.il Theodoros Theodosiou, Associate Professor Laboratory of Building Construction & Building Physics, School of Civil Engineering Aristotle University of Thessaloniki Building E10, University Campus 54124 Thessaloniki, Greece t: +30 2310 995 818 e: [email protected] auth.gr/en/civil

Tanya Saroglou, PhD is a qualified architect in the UK (ARB) and Greece (TEE), with experience in architectural design and project management. In 2003 she completed her diploma in architecture at Kingston University. In 2006, she was awarded the Professional Practice and Management in Architecture from the Bartlett, University College London, and in 2013 an MSc in Sustainable Design from the University of Edinburgh. She has just completed her PhD studies at Ben-Gurion in Israel, via a thesis titled: “Design Strategies Towards More Energy-Efficient High-Rise Buildings,” and continues the research as a post-doctorate student. Her research so far has yielded three Q1 peer reviewed papers, and four papers published in peer-reviewed conference proceedings. Isaac A. Meir, PhD is affiliated with the Desert Architecture & Urban Planning Unit (since 1986), and Structural Engineering Department, Faculty of Engineering Sciences (since 2018) at Ben-Gurion University. Meir participates in the design of environmentally conscious, experimental projects in deserts. He is a consultant to Israel’s ministries of Construction and Housing, Energy, Water and Infrastructures, the Israel Land Administration, and the Standards Institute of Israel. Meir heads multidisciplinary teams focusing on green technologies and sustainable development. Research interests include sustainable design in arid zones; post-occupancy evaluation; indoor environment quality; life cycle energy analysis; zero-energy settlements; energy and tall buildings. He is the recipient of the Israel Green Building Council Award for Leadership in Green Building (2016). Theodore Theodosiou, PhD is an associate professor at the Laboratory of Building Construction & Building Physics in the Civil Engineering Department of the Aristotle University of Thessaloniki. His research interests include building energy efficiency, building physics, energy simulation of buildings, low-, passive- and near-zero-energy buildings. He has participated in various research programs, more than 80 national and international conferences, published chapters in scientific books, has published 35 papers in peer-reviewed scientific journals with more than 870 references.

Façades | 21CTBUH Journal | 2020 Issue II

reducing energy loads, by acting as a mediator between indoor and outdoor conditions (Cheung, Fuller & Luther 2005; Saroglou et al. 2017). A vital consideration in this relationship is the climatic conditions of the building’s location. So, by designing a climatically responsive building envelope that interacts appropriately with the ambient climatic conditions, it is possible to take advantage of passive heating and cooling techniques, and reduce the operational energy, i.e., heating and cooling (Yik 2005; Choi, Cho & Kim 2012).

However, current architectural tendencies, initiated from the mid-20th century onwards, especially prominent in high-rise buildings, portray an increased transparency of the envelope, and lightness of the structure, resulting in high cooling and heating energy loads (Allard & Santamouris 1998). On the other hand, during the last few years, double-skin façades (DSFs) have gained popularity over single-skin curtain walls, as a more advanced envelope scenario that leads to improvements of the building’s energy performance (Wood & Salib 2013). But, despite the number of built DSF built projects, and the numbers of DSF studies conducted, design guidelines on DSF energy performance are lacking, especially in relation to local climate (Joe et al. 2014; Ahmed et al. 2015; Ghaffarianhoseini et al. 2016).

This paper studies the performance of a building envelope for a high-rise reference model at different heights, in the hot and humid climate of Tel Aviv. The Tel Aviv climate (in terms of dry-bulb temperature, relative humidity, wind speed, and wind direction) is shown in Figure 2. Heating and cooling load comparisons are made by gradually upgrading the thermal properties of the building envelope for improving energy efficiency. Studies in hot climates are of special importance, due to the increased solar gains entering a glass façade, intensifying the cooling requirements. In addition, most research on double-skin envelopes, the focus of this study, has predominantly been undertaken in cold and temperate climates, with limited research

taking place in hot ones (Hamza 2008; Pomponi et al. 2016; Halawa et al. 2018).

Design Considerations for High-Rise Energy Efficiency

The Effect of Height on High-Rise Energy Loads A building interacts with the outdoors through the envelope (walls, roof, windows) generally, and specifically with the thermal properties of the materials that make up the building envelope. When estimating the energy loads of a high-rise building, it becomes important to take into consideration the changing microclimate with height, and how this affects the materials of the building envelope, through heat exchange with the ambient air by

Figure 1. Tel Aviv skyline. © Antony Wood





Wind Speed (m/s)

ºCm/s

Months of the Year

W/m2

%450

400

350

300

250

200

150

100

50

0

30

25

20

15

10

5

00 1 2 3 4 5 6 7 8 9 10 11 12





Wind Speed (m/s)

ºCm/s

Months of the Year

W/m2

%450

400

350

300

250

200

150

100

50

0

30

25

20

15

10

5

00 1 2 3 4 5 6 7 8 9 10 11 12

Figure 2. Tel Aviv annual climatic data. Source: EnergyPlus

28 | Codes and Regulations CTBUH Journal | 2020 Issue II

Chicago Building Code Modernization: Comparison of Prototype Building Designs

Codes and Regulations

Background

For many years, local design and construction industries understood there was a need to better align Chicago’s Building Code (CBC) with more modern codes and standards used throughout the US. Through collaboration with many departments within the City of Chicago, the Mayor’s Office, and more than 150 volunteer technical experts and industry leaders, the Chicago Building Code was comprehensively revised in 2019. The revised structural requirements are based upon the International Building Code (IBC)—the modern national standard, while maintaining and introducing special Chicago-specific provisions.

As part of the new code adoption process, projects filed between 1 December 2019 and 1 August 2020 will have the option of using a design methodology based on the original (pre-2019) CBC or the new 2019 CBC, which references the 2018 IBC. After 1 August 2020, all new designs submitted for approval will need to conform to the new 2019 CBC.

Study Objective and Scope

Structural engineers familiar with the CBC and IBC recognize that design lateral forces developed by the two codes can vary significantly. Low-rise buildings may realize a reduction in wind loads with the IBC, but as a

Abstract

This research paper, an abridged version of a white paper produced by the Chicago Chapter of the Council on Tall Buildings and Urban Habitat (CTBUH), reviews the potential impact of changes to the city’s building code as it is adapted to the International Building Code standard. Its main objective is to uncover the effect of IBC loading standards on the structural designs of a range of taller buildings in Chicago that may utilize prescriptive code design methodology, to assess the cost implications of a change in loading standards, and to assess the effect of IBC’s seismic loading requirements on representative local building projects.

Keywords: Chicago Building Code, International Building Code, Structural Engineering, Tall Buildings

building gets taller and the exposure category increases (as specified by ASCE 7 Exposure Category B to D), wind loads can significantly increase. Additionally, the IBC requires that designs consider seismic loading, so heavier low-rise buildings may also see an increase in demand from new code loading.

The study presented in this paper attempts to answer the following questions:

• How does the IBC loading affect the structural designs of a range of taller buildings in Chicago that may utilize prescriptive code design methodology?

• How significant is the impact to structural cost?

• How does seismic loading impact these sample building designs?

In order to gain insight into these questions, three prototype buildings were analyzed and designed according to both CBC and IBC. The prototype buildings considered do not represent the full range of Chicago’s building stock, but are representative of the building types that are less than 400 feet (122 meters) tall, and as a result can utilize prescriptive code provisions for design (i.e., no wind tunnel testing). Additionally, a low-rise reinforced concrete office building is also considered for study, since short and heavier buildings are more susceptible to seismic loading.

Matthew Cummins

Daniel Koch

Authors

John Viise, Managing Principal Matthew Cummins, Project Engineer Alberto Guarise, Senior Project Engineer Daniel Koch, Project Engineer DeSimone Consulting Engineers 150 North Wacker Drive, Suite 2660 Chicago IL 60606 United States t: +1 312 493 4100 e: [email protected] de-simone.com

John Viise is the Managing Principal of DeSimone’s Chicago office. For over 25 years, Viise has been providing structural services for high-rise and special-use structures throughout the world. He is at the forefront of technical design, through active participation in industry research and knowledge sharing. Matthew Cummins currently serves as a Project Engineer in DeSimone’s Chicago office where he actively supports the firms Structural Engineering and Forensics practices. Cummins has over seven years of experience in structural analysis, design, detailing and construction administration on numerous new building and retrofit projects. Alberto Guarise currently serves as a Senior Project Engineer in DeSimone’s Chicago office. Guarise has over eight years of experience providing design and construction phase services in two major metropolitan areas: New York and Chicago, including high-rise and medium-rise office, residential developments, and sports arenas. Daniel Koch currently serves as a Project Engineer in DeSimone’s Chicago office where he actively supports the firms Structural Engineering and Forensics practices. His project experience includes: commercial, education, energy, and government facilities design.

John Viise

Alberto Guarise

Codes and Regulations | 29CTBUH Journal | 2020 Issue II

Figure 1. Isometric view of the prototype buildings.

The three prototype buildings examined as part of this research paper are shown in figures 1 and 2 and a detailed description of each is provided below.


Prototype Building 1 is a residential tower with a 15-foot, 8-inch (4.8-meter) ground floor lobby and 36 floors at a 10-foot, 8-inch (3.3-meter) floor-to-floor height. The building roof has an elevation of 399 feet, 8 inches (121.8 meters) (see Figure 1), just below the 400-foot (121.9-meter) threshold requirement for wind tunnel testing per IBC.

The floor plate is 100 feet (30.5 meters) square, with columns around the perimeter spaced at 30 feet (9.1 meters) on center (see Figure 2). Elevated floors are 8-inch- (203-millimeter)-thick post-tensioned concrete slabs. The lateral system consists of a concrete bearing shear wall core with dimensions of 44 feet, 9 inches (13.6 meters) and 30 feet (9.1 meters). The core has web walls at the elevator and stairs that are 10 inches (254 millimeters) thick and are included in the analysis model. Concrete link beams at the core wall door rough openings are 29 inches (737 millimeters) deep and match the thickness of the shear walls. This corresponds to a door opening height of 8 feet, 3 inches (2,514 millimeters). Widths used for the door rough openings are 4 feet (1,219 millimeters) for single doors, and 8 feet (2,438 millimeters) for double doors.


Prototype Building 2 is an office building with a 20-foot (6.1-meter) ground floor lobby and 19 floors at a 14-foot (4.3-meter) floor-to-floor height. The building roof has an elevation of 286 feet (87.2 meters) (see Figure 1). An exterior windscreen extends an additional 14 feet (4.3 meters) forming a mechanical penthouse for a total building height of 300 feet (91.4 meters) above grade.

The floor plate is 180 feet by 130 feet (54.9 meters by 39.6 meters). Columns are spaced

on a 30-foot (9.1-meter) grid in the longitudinal direction with 45-foot (13.7-meter) lease spans on each side of an interior 40-foot (12.2-meter) bay (see Figure 2). The floor system consists of 3-1/4-inch (83-millimeter) lightweight concrete on a 3-inch (76.20-millimeter) metal deck supported by structural steel infill framing at 15 feet (4.6 meters) on center. The lateral system consists of a concrete bearing shear-wall two-bay core, centered in the building with overall dimensions of 60 by 40 feet (18.3 by 12.2 meters). Concrete link beams at the core wall door openings are 36

Prototype 1

37-story Residential Tower 400 feet (121.9 meters) tall 100 x 100 feet (30.5 x 30.5 meters)

Prototype 2


Prototype 3


inches (914 millimeters) deep and match the thickness of the shear walls. This corresponds to a door rough opening height of 11 feet (3,353 millimeters). Widths used for the door rough openings are 8 feet (2,438 millimeters).


Prototype Building 3 is an office building with a 20-foot- (6.1-meter)-high ground floor lobby and 9 floors at a 14-foot (4.3-meter) floor-to-floor height. The building roof has an elevation of 146 feet (44.5 meters) (see Figure 1).

“The Chicago Wind Climate model suggests that wind loading from the easterly winds is expected to be significantly lower than prevailing strong winds from south and west.”

36 | CTBUH Special Report: Tall + Urban Innovation CTBUH Journal | 2020 Issue II

In this paper, innovations in the constituent disciplines that bring tall buildings to life, and even extend their lives— architecture, construction, renovation, the engineering of façades, fire & risk, geotechnical engineering, interior space, MEP, and structural engineering—are all explored. By diving into such details, a comprehensive portrait of the tall building world emerges, and a number of trends, some summarized below, come into focus. Here, we gather together the projects that are most representative of the dominant trends in, as well as the highest aspirations achieved by the tall building industry in 2020.

One Thousand Museum, Miami. © Alëna Graff ARO, New York. © CetraRuddy Architecture DaiyaGate Ikebukuro, Tokyo. © NIKKEN SEKKEI LTD.

Urban Allure

New design-forward residential projects are cropping up on dense urban corners all over the world, some of them in neighborhoods in major cities not typically known for their domestic offerings. But as demand for uncompromising homes in downtown cores continues to gather momentum, giving the “suburban ideal” a run for its money, these projects boast lavish amenities, impeccably designed interiors, and sculptural, evocative morphology.

2020 Tall + Urban Innovation: Dominant Trends

CTBUH Special Report: Tall + Urban Innovation

Abstract

Providing a global overview of tall building development, design and construction, the CTBUH Awards Program annually survey projects, technologies, and approaches currently reshaping skylines and urban spaces. As much as skyscrapers are celebrated for their iconic presence on the skyline, the projects showcased here, all recipients of a CTBUH Award of Excellence in the 2020 program, attest to the growing investment the tall building industry has made in city-making. The singular focus on skyline presence and attribution to an individual architect or financial mastermind has served the mythology of the skyscraper well, but the reality is something altogether different.

Keywords: Best Tall Buildings, CTBUH Awards, Innovation, Sustainability, Urban Habitat

In Miami’s downtown, long known for its arts, shopping and dining, One Thousand Museum (Best Tall Building, 200–299 meters) dubbed the “Scorpion Tower” due to its exterior bracing that resembles an arthropod, makes a splash on the residential market with its futuristic façade.

The striking silhouette of OMNITURM (Best Tall Building, 100–199 meters) brings new life to a cluster of corporate headquarters in downtown Frankfurt. The slender and rationally stacked tower is interrupted by sculptural shift in its mid section, where its program changes to residential. The floor

CTBUH Special Report: Tall + Urban Innovation | 37CTBUH Journal | 2020 Issue II

Leeza SOHO, Beijing. © Cao Baiqiang

plates slide out in a spiralling movement, creating terraces and overhangs for enhanced city living.

A layered building skin with solar refracting properties adds visual intrigue to ARO (Best Tall Building, 200–299 meters), a slender, residential tower in New York City’s theater district. The building’s unconventional shaping distributes unit size, mix, and program from top to bottom, as well as providing a generous suite of amenities.

Making Way

As urban environments continue to densify, finding spacious, undeveloped sites on which to build new vertical projects becomes increasingly challenging without costly demolitions that produce disruption and debris. Then there is the matter of pre-existing infrastructure or heritage projects that are an indelible part of the neighborhood, both of which may require innovative workarounds, resulting in the slotting of complex projects into compact sites.

This is exemplified in dense Asian cities like Tokyo, where projects such as DaiyaGate Ikebukuro (Structural Engineering), creatively use unconventional spaces. By hovering over the tracks of the Seibu line, it provides a connection between two sections of the busy Ikebukuro Station, helping to consolidate busy commuter flows for a more streamlined experience, and stitching together two sides of a divided neighborhood. Space is also particularly tight in China’s capital city, where the soaring, full-height atrium of Leeza SOHO (Best Tall Building, 200–299 meters) unites the tower’s two volumes, split diagonally by a new underground rail line.

In one of Melbourne’s historic precincts, 271 Spring Street (Best Tall Building, under 100 meters) deftly navigates around a bevy of site-specific challenges on its already limited plot—underground rail loop tunnels through the center of the site, an electricity sub-station, two high-voltage easements,

two preserved buildings, and an archeological overlay—to build a new, cantilevered office tower with façade screen elements that reinterpret the heritage roof geometry below.

In another example of turning spatial quandaries into remarkable designs, Shanghai’s InterContinental Shanghai Wonderland Hotel (Fire & Risk Engineering) didn’t have to contend with existing rail or utility lines; in fact it had a quite particular problem: building into the side of quarry on

271 Spring Street, Melbourne. © ISPT Pty Ltd

the outskirts of the city gave it a completely blank slate, except for the pockmarked canyon it had to transform into a resort. But transform it did, using the quirks of the quarry to give the hotel a distinctive setting. Further, it confronted a huge and nearly unprecedented obstacle to evacuation, literally turning “upside down” most of the conventions of tall building egress.

In some cases, making way might mean finding a method for removing defunct infrastructure that is inhibiting useful

InterContinental Shanghai Wonderland Hotel, Shanghai. © Shimao Group

44 | CTBUH Research Report CTBUH Journal | 2020 Issue II

In 2012, the CTBUH Journal published a research paper titled “Tallest 20 in 2020: Era of the Megatall—The Projected World’s Tallest 20 Skyscrapers in the Year 2020.” Though it was only eight years ago, the pace of change in the tall building world at the time was such that 2020 seemed like a distant lodestar in the future. The future, of course, has the inconvenient habit of appearing in the present far too early for the comfort of most. Today, the CTBUH Research and Editorial teams review the projections we made in 2012, the assumptions that guided them, and the roller-coaster reality of what has come hence.

Prediction 1 “By 2020, we can expect that at least eight megatall buildings (of 600 meters’ or greater height) will exist worldwide.”

Reality In the second quarter of 2020, there are three megatall buildings in existence. These are the Burj Khalifa, Dubai (828 meters); Shanghai Tower, Shanghai (632 meters); and Makkah Royal Clock Tower Hotel (601 meters), Mecca (CTBUH Skyscraper Center 2020).

What Happened? Five of the eight megatall buildings projected in 2012 to complete by 2020 did not achieve that goal. Here are their stories:

Wuhan Greenland Center, Wuhan • Predicted 2020 rank in 2012: 7 (606 m)• Actual rank in 2020: n/a (476 m)*

The Wuhan Greenland Center had been designed to rise to 606 meters with a curved

crown, but construction had already begun when aviation authorities then intervened, concerned that future flight paths around Tianhe International Airport would be curtailed if towers in the city rose to that height (see Figure 1). The compromise design, with a similar curved top but wider proportions, will rise to 476 meters, knocking Wuhan Greenland Center from a 2012–predicted number 7 rank in 2020 and out of “megatall” status. If completed today, the still under-construction building would be the world’s 23rd-tallest building.* It is currently difficult to predict a final completion date, however, due to the developer’s alleged failure to make payments to the contractor. In October 2019, the contractor removed all

The Tallest 20 in 2020: Then and Now

CTBUH Research Report

Abstract

This research paper undertakes a review of the 2012 report by the Council on Tall Buildings and Urban Habitat, “Tallest 20 in 2020: Entering the Era of the Megatall,” assessing the accuracy of the predictions made at that time against the reality of the present day. It reviews the development trajectory of CTBUH’s 2012 predicted and unanticipated 20 tallest buildings in the world in the year 2020, and places the results in regional, industry and historical context.

Keywords: Development, Economics, World’s Tallest Building

Figure 1. Wuhan Greenland Center, Wuhan, was intended to be a “megatall” at 606 meters (left) but was cut down by aviation authorities, to 476 meters (right). © AS+GG (left); Baycrest (cc by-sa) (right)

its workers from the site until the dispute could be settled (Sun 2019).

Jeddah Tower, Jeddah• Predicted 2020 rank in 2012: 1 (828 m)• Actual rank in 2020: n/a Jeddah Tower, which began construction in 2013 and was then called Kingdom Tower, has experienced numerous delays and remains under construction in 2020. News reports peg a “topping out” by the end of 2020, but it is unclear when completion may finally happen (Gibbon 2020). If it were completed now, and for some time in the foreseeable future, it would become the World’s Tallest Building at more than

CTBUH Research Report | 45CTBUH Journal | 2020 Issue II

Figure 2. Ping An Finance Center, Shenzhen–proposed in 2008 and originally set to rise 660 meters (left), it was completed in 2017 at 599 meters (right), due to changes in aviation restrictions. © Kohn Pedersen Fox Associates (let); Tim Griffith (right)

1,000 meters (the exact height figure remains undisclosed).

Seoul Light DMC Tower, Seoul• Predicted 2020 rank in 2012: 4 (640 m)• Actual rank in 2020: n/a The predicted world’s fourth-tallest building in 2020 was expected to reach 640 meters. In 2012, the contractor that had intended to construct the building failed to pay for the land plot, and the project was scrapped (Bae 2015). Discussions have been ongoing since 2015 to restart the project, potentially with a shorter tower (Kim 2018).

Signature Tower, Jakarta• Predicted 2020 rank in 2012: 4 (638 m)• Actual rank in 2020: n/a* The Signature Tower in Jakarta, proposed in 2009, at 638 meters, was anticipated in 2012 to become the world’s fifth-tallest building by 2020. However, multiple design changes and failed geotechnical/hydrological tests caused the first round of delays (Alexander 2014). The project eventually received design approval from local authorities in 2015, and approval for construction in 2017 (Alexander 2015a, 2015b; Freycinetia & Puspa 2017). However, it was still short some US$1.7 billion in funding, and remains stalled (Dwijayanto 2018).

This is not to imply that the road had been smooth for the three megatalls that did complete, however—or for that matter, for practically any of the buildings on the 2020 World’s Tallest List, then or now.

Burj Khalifa, Dubai• Predicted 2020 rank in 2012: 2 (828 m)• Actual rank in 2020: 1 (828 m) The Burj Khalifa, completed in 2010, became the World’s Tallest Building at that time and retains the title today. Its iconic status has driven much development around its periphery, delivering value above and beyond the building itself. Its grand opening was in January 2010, which coincided with a name change from “Burj Dubai” after Sheik

Khalifa bin Zayed al-Nahyan provided financial assistance to finish the project (Thomas 2010). It was declared the World’s Tallest Building by the Council in March 2010 (CTBUH 2010).

Ping An Finance Center, Shenzhen• Predicted 2020 rank in 2012: 3 (660 m)• Actual rank in 2020: 4 (599 m) Like its cousin in Wuhan, Ping An Finance Center received a “haircut” due to aviation restrictions being imposed after the buildings had been designed. The office building was originally intended to reach 660 meters by way of a spire at its top (see Figure 2). During the design process, local aviation authorities, concerned that a building of that height might impede the range of potential flight paths in and out of

Shenzhen Bao’an International Airport, restricted its height to 600 meters, maximum. The redesign completed the building’s architectural expression with a pyramidal crown, bringing its final height to 599 meters—and thus removing the classification of “megatall.”

Shanghai Tower, Shanghai• Predicted 2020 rank in 2012: 6 (632 m)• Actual rank in 2020: 2 (632 m) While Shanghai Tower didn’t break ground until 29 November 2008, plans for a tower on the Lujiazui financial district site emerged as early as 1993, with a group of three towers; Jin Mao Tower (1999) and Shanghai World Financial Center (SWFC) (2008) comprising the two “sisters” of a “three sisters” tower plan. Shanghai Tower completed in 2015, but had

* Buildings must be fully clad and ready for occupancy in order to qualify as “complete” by CTBUH criteria, and to be officially entered into height rankings.

52 | Tall Building in Numbers CTBUH Journal | 2020 Issue II

Tall Buildings in NumbersTall Buildings in Numbers

In the first edition of the 2012 Journal, CTBUH published a Tall Buildings in Numbers study titled Tallest 20 in 2020: Era of the Megatall—The Projected World’s Tallest 20 Skyscrapers in the Year 2020. Now that we have arrived at the second edition of 2020, we look back on the fates of each of the buildings predicted to be the tallest in existence this year—and those that actually did make the list. This report serves as a companion to the research paper beginning on page 44, which provides more background. For an interactive version, and a link to the original article, visit skyscrapercenter.com/tallest-in-2020.

The Tallest 20 in 2020: Predictions vs. Reality

The 20 Tallest Buildings in 2020

Three of the 20 buildings on the original 2012 list were not completed as planned, due in part to aviation restrictions after the projects had already begun.

The Burj Khalifa began life as the “Grollo Tower”—a 1990s development concept, originally proposed for Melbourne, Australia.

In this graphic, the 20 tallest buildings in 2020 are shown in the foreground, while the skyline that was originally predicted in 2012 is shown in gray in the background.

1. Burj KhalifaDubai 828 m

2. Shanghai Tower Shanghai 632 m

6. One World Trade Center New York City 541 m

5. Lotte World Tower Seoul 555 m

9. CITIC Tower Beijing 528 m

10. TAIPEI 101 Taipei 508 m

3. Makkah Royal Clock Tower Mecca 601 m

=7. Tianjin CTF Finance Centre Tianjin530 m

4. Ping An Finance Center Shenzhen599 m

1. Jeddah Tower (2012 Name: Kingdom Tower)Jeddah, 1,000+ m

8. Makkah Royal Clock Tower HotelMakkah601 m

9. Goldin Finance 117Tianjin 597 m

7. Wuhan Greenland Center Wuhan606 m

6. Shanghai TowerShanghai632 m

5. Signature Tower Jakarta Jakarta638 m

4. Seoul Light DMC Tower Seoul640 m

3. Ping An Finance CenterShenzhen660 m

2. Burj Khalifa Dubai828 m

10. Lotte World Tower Seoul555 m

If each building had been constructed in sequence, the Tallest 20 in 2020 would have taken 126 years to complete.

=7. Guangzhou CTF Finance Centre Guangzhou 530 m

Tall Building in Numbers | 53CTBUH Journal | 2020 Issue II

While the timeline below shows the progress of each building between 2012 and 2020, some buildings completed prior to 2012.

What Happened to the 2012 Predicted Tallest 20 Skyline?

In 2012, South Korea was predicted to have three of the world’s tallest buildings by 2020. Instead it has only one—but Lotte World Tower, Seoul, is the world’s � fth-tallest building.

11. Shanghai World Financial Center Shanghai492 m

18. Suzhou IFS Suzhou 450 m

19. Zifeng TowerNanjing 450 m

20. The Exchange 106 Kuala Lumpur 445 m

12. International Commerce Centre Hong Kong 484 m

13. Lakhta Center St. Petersburg 462 m

14. Vincom Landmark 81 Ho Chi Minh City 461 m

15. Changsha IFS Tower T1 Changsha 452 m

=16. Petronas Twin Towers 1 & 2 Kuala Lumpur 452 m

19. Kaisa Feng Long Centre Shenzhen500 m

18. TAIPEI 101Taipei508 m

17. Busan Lotte Town Tower Busan 510 m

16. PentominiumDubai516 m

15. Dalian Greenland CenterDalian518 m

=13. Tianjin CTF Finance Centre (2012 Name: Tianjin Chow Tai Fook Binhai Center), Tianjin530 m

=13. Guangzhou CTF Finance Centre (2012 Name: Chow Tai Fook Guangzhou) Guangzhou530 m

12. One World Trade CenterNew York City541 m

20. Shanghai World Financial Center Shanghai492 m

11. Doha Convention Center and TowerDoha551 m

The Goldin Finance 117 tower was modeled after a walking stick.

The sum of heights of the actual 20 Tallest Buildings in 2020 is 10,452 meters, compared to 11,953 for the 2012 projection.

2012 2013 2014 2015 2016 2017 2018 2019 2020

1. Jeddah Tower (Kingdom Tower)

2. Burj Khalifa (2010)

3. Ping An Finance Center

4. Seoul Light DMC Tower

5. Signature Tower Jakarta

6. Shanghai Tower

7. Wuhan Greenland Center

8. Makkah Royal Clock Tower

9. Goldin Finance 117

10. Lotte World Tower

11. Doha Convention Center Tower

12. One World Trade Center

=13. Guangzhou CTF Finance Centre(Chow Tai Fook Guangzhou)

=13. Tianjin CTF Finance Centre(Tianjin Chow Tai Fook Binhai Center)

15. Dalian Greenland Center

16. Pentominium Tower

17. Busan Lotte Town Tower

18. TAIPEI 101 (2004)

19. Kaisa Feng Long Centre

20. Shanghai World Financial Center (2008)

1

3

2

5

=7

10

11

=7

6

#Key: Completed, current rank Under Construction Proposal

500m proposal redesigned into a 250m building

4Height changes from 660m to 599m

Proposal height changes from 606m to 636m Height changes from 636m to 476m On hold

Never completed

On hold

On hold

On hold

Δ 1,501meters

2012 2013 2014 2015 2016 2017 2018 2019 2020

1. Jeddah Tower (Kingdom Tower)

2. Burj Khalifa (2010)

3. Ping An Finance Center

4. Seoul Light DMC Tower

5. Signature Tower Jakarta

6. Shanghai Tower

7. Wuhan Greenland Center

8. Makkah Royal Clock Tower

9. Goldin Finance 117

10. Lotte World Tower

11. Doha Convention Center Tower

12. One World Trade Center

=13. Guangzhou CTF Finance Centre(Chow Tai Fook Guangzhou)

=13. Tianjin CTF Finance Centre(Tianjin Chow Tai Fook Binhai Center)

15. Dalian Greenland Center

16. Pentominium Tower

17. Busan Lotte Town Tower

18. TAIPEI 101 (2004)

19. Kaisa Feng Long Centre

20. Shanghai World Financial Center (2008)

1

3

2

5

=7

10

11

=7

6

#Key: Completed, current rank Under Construction Proposal

500m proposal redesigned into a 250m building

4Height changes from 660m to 599m

Proposal height changes from 606m to 636m Height changes from 636m to 476m On hold

Never completed

On hold

On hold

On hold

54 | Talking Tall: Walter Hughes CTBUH Journal | 2020 Issue II

Talking Tall: Walter Hughes

How did your firm become interested and involved in architecture around flying taxis and drones? We started looking at that many years ago. We did a building in Dubai in the early 2000s, and placed some landing structures on it without thinking too much about it. But then, in 2016, we did the first “apartment of the future.” For that project, we not only had flying taxis or electric vertical-takeoff-and-landing vehicles (eVTOLs), but also drone deliveries. We thought, “how would it change tall buildings when drones start delivering packages?” We had already started to see the impact of the huge growth of package deliveries in our projects, which would typically have a small storage space inside the leasing area, that were becoming overwhelmed daily due to volume growth of

For several years, Dallas-based architecture firm Humphreys & Partners has been involved in numerous forward-looking design projects that anticipate the increasing presence, if not ubiquity, of manned and autonomous flying vehicles, such as drones and “air taxis.” These include a technologically advanced high-rise called “Pier 2” as well as a “skyport” for Uber Elevate, the ride-sharing company’s air-taxi venture. Walter Hughes, Chief Innovation Officer at Humphreys, spoke with Daniel Safarik about the firm’s future high-rise visions. Walter Hughes

High-Rise “Vertiports” and Other Near-Future Visions

Figure 1. Pier 2, a speculative high-rise project set in lower Manhattan, combines numerous drone- and flying-vehicle-related facilities. © Humphreys & Partners

Interviewee

Walter Hughes, Chief Innovation Officer/ Vice President Humphreys & Partners Architects 5339 Alpha Road Suite 300 Dallas, TX 75240 United States t: +1 972 701 9636 f: +1 972 701 9639 e: [email protected] humphreys.com

Walter Hughes possesses over 27 years of experience in the architectural and planning field, bringing a wide range of design knowledge and insight to Humphreys & Partners. Currently, he serves as Chief Innovation Officer, where he leads a team of architectural and 3D experts to identify, evaluate, and assess the future potential of new technologies, designs, and processes. He consistently demonstrates a unique ability to bridge the understanding between conceptual ideas and real architectural form, producing revolutionary solutions and forward-thinking designs used and lauded worldwide.

about 1 percent per month. These were conventional truck deliveries, of course, but then we saw that Amazon and others were developing drone delivery, and realized this was something we needed to look into.

So, in 2016 we started planning for it. In 2018, we did the apartment building Pier 2 in New York as a speculation, and it had the landing pads and everything else more sorted out (see Figure 1). Both manned flying vehicles and drone deliveries were taken into account. That got noticed, and we started growing our drone-based designs, and that led us to being invited to a large competition organized by Uber to design “mega-skyports.” These were to be structures able to handle 1,000 takeoffs and landings per hour, on a space of 3 acres (1.2 hectares). We were selected as one of the four finalists and invited to present our concept at Uber Elevate in Los Angeles in May 2018—that’s when we really started getting into it (see Figure 2). We got all the regulations, models and requirements, so we really learned about what was going on and what needed to happen. We learned what we, as a firm, would need to do to be ready for such a development. Uber ran the competition again in 2019, and we were again selected to present at Uber Elevate 2019 in Washington, DC.

Is this entirely speculative, or are you hearing from your client base that they want to have high-rises developed that incorporate provisions for VTOL vehicles and drones? I think there’s a lot of curiosity and people are asking about it. Most people I talk to seem skeptical about the whole thing, and they don’t realize that it’s something that’s going

Talking Tall: Walter Hughes | 55CTBUH Journal | 2020 Issue II

Figure 2. Volary is a “skyport” designed for Uber Elevate, the ride-hailing company’s aviation division. © Humphreys & Partners

to hit us in the next 10 to 15 years. We have not built any building yet with landing capabilities for drones in the sense that Uber is planning on doing. We have heliports, and similar structures, but there are still a lot of issues to overcome before developers start planning to have them in their buildings. Everybody’s asking about them, but they’re not building them. There’s a lot of “waiting and seeing.”

Does that have more to do with the flying technology or the buildings? The technology, for the most part, is there already. The biggest issue is regulation, which one of the biggest hurdles to these machines becoming an everyday part of your life. Regulating these vehicles is a very complex issue that falls under the jurisdiction of several agencies—and rightly so; safety is priority number one. The other issue is affordability. The dollars per mile are coming down every year, but they’re still noncompetitive at this point. Drone deliveries are strictly regulated, and we have provided landing pads for them in some cases, but that is not as cost-intensive as building a platform that can handle 150 flights an hour, and not only that—it also needs to move several hundred people an hour through a building and connect to all other urban mobility systems, including traditional modes.

So, there are drones delivering packages to your buildings, but not people? Correct. While drones delivering people will take a few more years to become a reality, package delivery via either surface or air is already here. There are several companies working on this, including UPS, Wing (an offshoot of Google’s parent company Alphabet), Amazon, and Uber. Some of them have recently received clearance from the Federal Aviation Administration (FAA) in certain parts of the United States.

There is more difficulty around carrying passengers to and from tall buildings. Safety and regulations are prime concerns, but cost is an issue as well. These vehicles that are being developed right now have the capacity for four or five passengers. If you

add the cost of a pilot to operate the vehicle, then the cost goes up exponentially, through the roof. At this point, the population isn’t ready yet for flying in an electrically powered, automatically piloted vehicle. Public acceptance is not there yet. It might be a few years before people get into one of those. Initially, in the first few years we will see eVTOLs that are flown by highly trained pilots, transporting four or five people, which is outrageous in terms of cost. This is compounded by the fact that there is already a pilot shortage in the aviation industry, certifications need to be issued, and coordination with air traffic control needs to be undertaken.

And it is more complicated to design for the newer vehicles than with traditional helicopters and helipads, because the current battery endurance for eVTOLs is not where we would like it to be. They have to be recharged fairly frequently. It’s not like you can charge an eVTOL and take it out in the morning and fly the whole day—they hold a charge for less than an hour on average. Essentially this means you have to charge

every time you land. You have to have one platform for charging and another for active takeoffs and landings.

On the autonomous side, you have the issue of cyber security and the threat of someone taking control of these vehicles, of which thousands could be flying through the city’s airspace. The technology for unmanned flying vehicles is ready—it’s just everything else around it that’s not. So, yes, packages are starting to be delivered by drones, but not people, just yet.

What are the accommodations you have made for package deliveries? Are there specialized trays or landing pavilions for drones? The answer varies depending on building types, but essentially, they all have a few things in common. They all need to handle everything from traditional online packages, to groceries and dry cleaning on a daily basis. We start by providing a drone landing pad, meeting certain regulations regarding clearances, etc. This could be on-grade or high up on the building. In tall buildings,

About the Council

ISSN: 1946 - 1186

The Council on Tall Buildings and Urban Habitat (CTBUH) is the world’s leading resource for professionals focused on the inception, design, construction, and operation of tall buildings and future cities. Founded in 1969 and headquartered at Chicago’s historic Monroe Building, the CTBUH is a not-for-profit organization with an Asia Headquaters office at Tongji University, Shanghai, a Research Office at Iuav University, Venice, Italy, and an Academic Office at the Illinois Institute of Technology, Chicago. CTBUH facilitates the exchange of the latest knowledge available on tall buildings around the world through publications, research, events, working groups, web resources, and its extensive network of international representatives. The Council’s research department is spearheading the investigation of the next generation of tall buildings by aiding original research on sustainability and key development issues. The Council’s free database on tall buildings, The Skyscraper Center, is updated daily with detailed information, images, data, and news. The CTBUH also developed the international standards for measuring tall building height and is recognized as the arbiter for bestowing such designations as “The World’s Tallest Building.”

CTBUH Headquarters 104 South Michigan Avenue, Suite 620 Chicago, IL 60603, USA Phone: +1 312 283 5599 Email: [email protected] www.skyscrapercenter.com CTBUH Asia HeadquartersCollege of Architecture and Urban Planning (CAUP) Tongji University1239 Si Ping Road, Yangpu District Shanghai 200092, China Phone: +86 21 65982972Email: [email protected] CTBUH Research OfficeIuav University of Venice Dorsoduro 2006 30123 Venice, ItalyPhone: +39 041 257 1276 Email: [email protected] CTBUH Academic OfficeS. R. Crown Hall Illinois Institute of Technology 3360 South State StreetChicago, IL 60616 Phone: +1 312 283 5646 Email: [email protected]

CTBUH Journal

Documents

Transcript of CTBUH Journal