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A Game of Towers: The Rise of High-Rise Architecture in the City of London



Studio London: Power - Space and Representation ONE UNDERSHAFT A Game of Towers: The rise of high-rise architecture in the City of London

Michael Van Steijvoort

Thesis voorgedragen tot het behalen van de graad van Master of Science in de ingenieurswetenschappen: architectuur. Promotor: Jan Vermeulen Co-promotor: Tom Thys

Academiejaar 2015-2016

Master of Science in de ingenieurswetenschappen: architectuur


Š Copyright KU Leuven Without written permission of the promotors and the authors it is forbidden to reproduce or adapt in any form or by any means any part of this publication. Requests for obtaining the right to reproduce or utilize parts of this publication should be adressed to dept. Architecture, Kasteelpark Arenberg 1/2431, B-3001 Heverlee, +32-16-321361 or via e-mail to secretariaat@ A written permission of the promotor is also required to use the methods, products, schematics and programs described in this work for industrial or commercial use, and for submitting this publication in scientific contests. All images in this booklet are, unless credits are given, made or drawn by the author.


K.U. Leuven Faculteit Ingenieurswetenschappen

2015 - 2016

Master’s thesis file


Michael Van Steijvoort


ONE UNDERSHAFT A Game of Towers: the rise of high-rise architecture in the City of London




Throughout most of its history, the skyline of the City of London has been marked by countless church spires which rose far above the generally low-rise , dense city fabric. More than just expressions of piety, these towers displayed the power and wealth of each parish in the City. For over a thousand years, St. Paul’s Cathedral in its many forms was the greatest of these ecclesiastical buildings. This image remained for centuries as London grew larger and expanded outside of its original walls. Even after the Great Fire of 1666, which consumed large swathes of the City, dozens of churches were redesigned and rebuilt by Sir Christopher Wren, thus introducing an immense architectural diversity in the City. Only after the devastating bombings of the Second World War, the image of the City started to change rapidly. Gradually, the City became the center of business while its actual population dropped, and office buildings quickly filled the scarce pieces of land in the Square Mile that were created during the War. When there was no space left, the need for more office space brought about new architectural typologies. Following the American fascination for glass-andsteel towers, the modernist podium-and-tower blocks of the sixties and seventies emerged in the City. They did not last long in a City whose public life relied on alleys, which left the raised podiums in desolation. Soon, these towers were replaced by massive post-modernist groundscrapers in the eighties and nineties, again introducing an abundance of new stylistic elements into the City. By the end of the twentieth century, the skyscraper was introduced in the City as a way to compete with the neighbouring business center of Canary Wharf and other financial hotspots in the world. While only one notable office skyscraper appeared in the City before the turn of the millenium, a large number of skyscrapers has risen in several clusters since the turn of the century. The once so present church spires are now dwarfed by the giant glazed skyscrapers which fill every empty spot in the medieval city fabric. Every year, new giants sprout in the City, each of them giving rise to endless debates between admirers and sceptics. While these buildings easily obstruct important views on certain landmarks, some of them also lack qualitative public space. Their privatized spaces at ground level, strictly monitored and supervized by security guards, are often windswept and unpleasant. In an attempt to maximize profits, they offer little more than a ground floor lobby with a stack of office floors. As a reply to these issues, my design proposal for an office tower at One Undershaft at the heart of the eastern office cluster, addresses these problems. The slim profile of the tower respects views in the skyline as well as on ground level. An open ground level with public functions at the first levels enables interaction with the public and makes sure that the space underneath and around the tower can be used both during and after office hours. A strongly connected system of sky lobbies and winter gardens provide plenty of opportunities for interaction between office workers, offering an alternative to the isolated office floors of most buildings.

Thesis submitted to obtain the degree of Master in Engineering: Architecture.

Promotor: Co-promotor: Readers:

ir. arch. Jan Vermeulen ir. arch. Tom Thys ir. arch. Bram Aerts ir. arch. Christopher Burton ir. arch. Filip Van de Voorde



I would like to express my sincere gratitude to all those who supported and guided me in the last year. First of all, special thanks go to my promotor Jan Vermeulen and co-promotor Tom Thys, who guided me through this journey and provided me with an inexhaustible amount of knowledge, for their endless patience and support. I would like to thank Peter W. Rees, former Chief Planning Officer of the City of London, for his captivating storytelling and passion for the City, Peter Murray, Chairman of New London Architecture, for his clear account on London’s highrise evolution, Robert White of the Council on Tall Buildings and Urban Habitat for his invitation to the panel discussion, and Barbara Weiss of the Skyline Campaign for her insightful interview and for her views on the changing skyline of London. For sharing their passion for architecture and for their precious time, I would like to thank Sergison Bates Architects, Caruso St. John Architects and David Chipperfield Architects. In addition, I would like to thank Walter SuvÊe of Sig Air Handling for his advice on the ventilation of the building. Most of all, a warm thank you to my family, girlfriend and friends, for their endless patience, love and friendship. Without them, this project would not have been possible.




1. A GAME OF TOWERS 11 A STORY OF STOREYS 13 An overview of the City’s significant changes in terms of its high-rise architecture

A FRAGMENT OF TIME 26 View of the City of London with its current high-rise buildings and the remaining churches

THREE TRIPTYCHS 29 Timeline showing the parallel evolution of highrise architecture in the City, together with important political, economical, historical and city planning events

CATALOGUE 39 Overview of the City’s high-rise architecture

BUILDING REFERENCE 43 Leadenhall Building, 122 Leadenhall Street


Introduction to the project of One Undershaft

II. THREE THEMES 52 Skyline 54 Public Space 58 Programme 62

III. CONSTRUCTIVE ASPECTS 66 Structural system 66 Elevation 67 East façade 69 External expression 70 South façade 71 Façade detail 72 Ventilation 74 IV. PROGRAMME OVERVIEW 76 Public floors 78 Visitor lobby & bars 78 Office lobby & restaurant 80 Event space & lecture hall 82 Collective functions 84 Sky lobby 84 Lower amenities 86 Conference rooms 88 Upper sky lobby 90 Upper amenities 92 Offices & wintergarden 94 Office typologies 96 Bicycle parking 98



PROLOGUE Studio London: Power - Space and Representation

THEME Cities have always been the place where values and ruling mechanisms of a society have been most apparent. The structure and organization of our built environment provides a multi-layered landscape that one can uncover. In each layer one can distill the ideas of those in power on how a society should be governed. This is expressed through the layout of streets, boulevards and squares, but also through the positioning of public institutions. In Brussels for example one can perceive this in the formal urban relation between the Royal Palace, the National Government and the Palace of Justice. This happens as well on a smaller scale. Town halls, libraries and churches define local centers. And maybe even more important, with their architecture, they express specific relations with the citizen; controlling and oppressing, or friendly and opening-up. The past decades have been dominated by important shifts in power. A combination of shrinking public funds and the need to develop a growth-economy that has become increasingly global, governments are now more and more reduced. As Noreena Hertz stated in her book ‘The Silent Takeover’, one can wonder if statepower slowly gets overpowered by the economical power of multinationals. In a time where non-globalists, glocalism and regional awareness test our current modes of building society, the spatial and architectural production that goes along with this new reality is highly under stress. With this studio we want to understand the driving mechanisms behind these invisible power actors. In a world without a moral distinction between good and bad, without a classical order as we know it, and in a world where everything is about identity, communication and perception, we discover new important challenges in the role of architecture. CONTEXT London is chosen as the locale of our fieldwork and design research. The city’s enormous concentration of both new and old power-actors makes it the European paradigm of the global power city. Through time it has accumulated large numbers of embassies, banks, institutions, societies and global corporations in an urban fabric that remains surprisingly historic. A planning system that is highly favorable towards private development makes London a hot-pit for profit driven real-estate transactions, resulting in a layered, fascinating urban scene where the public realm becomes increasingly dominated by the private sector. This questionable condition combined with a strong tradition of great architectural production makes London not only the perfect ground for critical analysis but also a great inspiration for meaningful architecture. STUDIO In this studio we want to investigate the mechanisms of how specific hidden power actors (from small lobby groups, clubs and embassies, to real estate organizations and large banks) produce space locally. Through research, fieldwork and mapping we will explore 2 areas in the London Metropolitan Area were a large concentration of power actors is dominating the urban realm. (Belgravia & the City) Firstly the goal is to build-up a thorough understanding of the mechanisms used by these power actors and develop a personal stance or opinion in relation to their role in society. Secondly we will explore the architectural and spatial typologies that house these power-actors and investigate how they, with the means of architecture, represent themselves in the public realm. Following clear methodologies for architectural production we will develop precise proposals for spaces and architectural representation. COLLABORATION With this design studio we seek to include a series of strong collaborations with local actors: the Greater London Authority, the local planning departments and representatives of power-actors. The site visit and documentation effort will be combined with a visit to relevant examples of buildings and spaces. Simultaneously we will offer students an inside view in the production of London architecture by visiting a number of renowned practices and universities. The thesis studio is developed as a collective “research by design” unit. Students will address different aspects of the urban and architectural conditions of London leading to both an architectural and urban design project (with the emphasis on design), based on the premise that physical form and the experience of city life are inseparable and in dire need of critical concepts that can address current evolutions in power representation. Studio London depends on design as the tool to transform, derail, reinvent and crossbreed existing modes of operations and their associated physical form. METHODOLOGY Research by design: The two semester Atelier is divided in several phases in which we explore different relations between design and research. The research project consists of a series of clearly defined products of different media: a text, a map, a photograph of a model respresenting an architectural space. Each of these products carry their own meaning and describe a part of the research carried out. The student is free to add a fourth medium, the ‘wild card’, to complement the research. The aim of this approach is not only to challenge existing way of developping a thesis project through linear story telling and replace it with a methodology that is based on analogy. It also aims to bring design more to the foreground. The goal is not to produce a booklet but a series of high quality products that are equally important. This methodology is then continued for the design project where students will again provide a text, a photograph of a model respresenting the design, and a set of of large drawings (possibly complemented with other material to support the main products. Both the research part and the design part form the thesis project. Each of the thesis proposals can be judged as personal work. As a group, the work is an assembly of different products exploring a collective theme through various media and interpretations allowing the results of the studio to be displayed and curated in many ways.

by Tom Thys, Jan Vermeulen






A STORY OF STOREYS An overview of the City’s significant changes in terms of its high-rise architecture


“Cities have always liked to mark their skylines to mark their power and wealth. It’s no different today, except that we are a largely secular society. If we mark our wealth in a skyline, it tends to be with secular buildings rather than religious ones.“ Peter Rees, former Chief Planning Officer of the City of London


A STORY OF STOREYS An overview of the City’s significant changes in terms of its high-rise architecture INTRODUCTION During most of its history, the City of London’s skyline was dominated by the steeples and towers of over one hundred churches that were spread out over the Square Mile, with the dome of Saint Paul’s Cathedral at its centre of gravity. In medieval times, it was common for each parish to mark its territory with a church. This was more than a religious expression. As London’s population grew richer through trade, citizens extended their church spires as a way of showing their wealth and power to their environment. The result of this was a low-rise city where churches determined the skyline. Only seventy years ago, this image started to change at an incredible pace. Starting with the post-war reconstruction of the war-damaged City and fueled by economic booms and global competition, the skyline transformed completely in just a few decades. Nowadays, the once so present church towers are dwarfed by the modern office buildings of the City’s insurance and banking industry. Their iconic skyscrapers are the physical embodiment of the liquid financial world and are a modern depiction of power. But for the City of London, building a high-rise cluster of skyscrapers was simply a necessity in order to maintain its top position as the world’s leading financial district. With cities like Frankfurt, New York and even the neighbouring Canary Wharf on their heels, the City needed to drastically change their century-old image to provide more office space. Many parties voiced their concerns about the seemingly unstoppable high-rise developments, claiming that the City’s historical character should be preserved. But if there is one certainty about London, it is the fact that it has adapted itself countless times throughout history. In the following part, the key periods in the City’s changing landscape will be discussed, in order to get a better understanding of how the City’s high-rise character came into existence and how it might evolve in the future. More than just a critique on the flaws of the architecture of the past and present, I will try to discover how we, as designers, can create buildings that are both efficient and provide a positive contribution to the fabric of London’s ever-changing City.


After the Great Fire: many spires, many styles

The medieval City had small churches on almost every street corner, adding up to a total of more than one hundred on the City’s tiny surface area. In the dense fabric of ramshackle homes that reached only two or three storeys high, these churches were already the highest buildings in their surroundings. Hardly a century after William the Conqueror’s Norman ancestors raided the east coasts of England and destroyed St Paul’s Cathedral in 962 (Gordon Meldon, 2014), the newly crowned king was determined to build the highest Christian church in the world, after its predecessor burnt down in 1087. Many people thought it would never be finished, and it took over one hundred and fifty years to do so, but with a height of 158 meters (Ward, Locke & Co, 1919), it remained the tallest building in the City by far for many centuries. Unfortunately, its spire collapsed due to a lightning strike in 1561, after which the cathedral started to decline, never to be properly repaired again (“Reformation to Conflagration”, 2016). Interestingly, this caused an unusual evolution in the building’s use. As religious functions disappeared, the cathedral became an ‘open house’, a commercial centre with market stalls, bookstores, a wine cellar and even a school. The nave was referred to as ‘Paul’s Walk’ (Clinch, 1906), a place where people came to hear news and gossip.


“If St Paul’s is Wren’s greatest memorial, the City of London churches come to a close second. And they share the same mythical status, defining the landscape of the capital in the eighteenth and nineteenth centuries, rising phoenix-like from the ashes of the Blitz in the twentieth.“ Adrian Tinniswood. From: His Invention So Fertile: A Life of Christopher Wren


As London grew bigger, it started to extend beyond its medieval walls and merged with Westminster, where the legislative and royal power was located. The ruling class had abandoned the crowded City a long time ago, but inside the City, a new form of power emerged. Business was thriving thanks to the City’s proximity to the Thames, and with it came new buildings like livery halls and the Royal Exchange, which followed the examples of European bourses like the one in Antwerp. Trading could now happen indoors. Gradually, the centre of gravity of the City’s power moved from the Church to those who made London’s economy boom. The power shift did not, however, have a clear influence on the City’s skyline. As these buildings for trading were relatively low-rise, churches remained the dominant structures for a whole lot of time. In 1666, a small fire in the King’s bakery escalated and destroyed most of the City in an inferno that lasted for almost five days (Ackroyd, 2003). St Paul’s cathedral, which had by then deteriorated so much that it could collapse any time, was completely destroyed, as well as the majority of the City churches. A few weeks after the Great Fire, architect Christopher Wren came with a plan to rebuild the entire City with a baroque street plan with Parisian boulevards and piazzas (Geragthy, 2007). The plan was quickly rejected for being too ambitious and expensive, but Wren was commissioned to rebuild most of the City’s churches. Although built in one architect’s lifetime, the churches of Wren show an enormous architectural diversity. In the fifty-odd churches that he designed, we can see roman, classicist, baroque, renaissance and gothic elements. The literal culmination of his work was the new St Paul’s Cathedral with its impressive triple-layered dome. It was the first cathedral that was built since the English Reformation, when the Church of England came under control of the Crown instead of the Pope. At the time of its completion, it had a controversial English baroque design, influenced by Wren’s studies of Rome, and was even called a ‘vulgar form of design’ (Glancey, 2011) as it showed resemblance to the papal, catholic architecture of Rome. Nevertheless, the domed church remains one of the most impressive works of architecture as of today. In the nineteenth century, London became the largest city in the world, with one million people living in 136,000 houses (Flanders, 2012). Among the many apartments that were built to house the rising number of residents was one development, located outside the City, that triggered the introduction of height restrictions in the London Building Acts of 1890 and 1894. These so-called Queen Anne’s Mansions were erected around 1873 between Victoria Street and St James’s Park, and became London’s first high-rise apartments (Dennis, 2008). The first stage of the building was a ten-storey block of thirty meter high, but gradually the building grew taller up to a height of 48 meters. Concerns arose for the fire safety of the building, as well as the loss of daylight on neighbouring buildings. Eventually, the London County Council imposed a height limit of eighty feet on new buildings.


After the War: the office boom

When the Blitz struck London, about one third of the entire City was completely destroyed, leaving large swathes of empty spaces ready to be redeveloped. Once again, London was facing the massive task of reconstructing most of its fabric. Although the priority of post-war reconstruction was the provision of housing and schools, the City of London and its office stock required attention, in order to maintain London’s leading position as a commercial centre. To increase the City’s office stock quickly, a building type called the ‘lessor scheme’ (Bullock, 2002) was introduced. Being completely devoid of architectural decoration or quality, it received plenty of criticism, after which it was soon abandoned. It was thanks to companies who decided to build on their own account, who wanted to represent their company through their building, that quality started to improve. The real change came during the 1960s, when the need for more office buildings caused a property boom. New regulations introduced plot ratios for the City of 5:1 or 5,5:1 around Bank, encouraging new developments to cover smaller parts of their site, and build higher instead (Bullock, 2002). Along with it came a new wave of visionary architects and planners, who called for an architectural revolution and who applied principles of Holford & Holden’s 1947 City of London Plan. In this plan, the separation of pedestrians 17

“[...] their idea was that the new architecture would be very much like the Bauhaus buildings, the latest of New York, the steel and glass towers. The key building that had affected them all was the Lever Building, designed in the fifties by the architects of SOM.� Jonathan Glancey talking about the London Wall podium-tower development in the fifties and sixties. From: The Pedway: Elevating London (Documentary)


and motorized traffic was the central idea. An ambitious project, inspired by Venice’s pedestrian bridges, was launched to cover the entire City with a thirtymile network of elevated walkways which would separate pedestrians and cars. This ‘pedway scheme’, along with the newly introduced plot ratios, radically changed the way buildings were related to the ground level, calling for a new typology for office buildings. Entrances of buildings were to be on the level of the walkway, and thus the tower-and-podium typology was created. The clearest example of this typology is the London Wall development, where six nearly identical towers were placed in a rigid scheme, perpendicular to a new dual carriageway and connected to the pedway network. This clear, almost monumental scheme with its geometric outlines was unique for the City and was clearly influenced by Le Corbusier’s Ville Radieuse. The towers of London Wall consisted of a two-floor base with a publicly accessible podium and sixteen floors above it. Shops and cafes were inserted in the raised level, in the hopes of attracting more people. Over the years, new developments were forced to provide the necessary space to connect the building to the pedway system. This created a fragmented network of disconnected walkways which soon proved to be an utter failure. The inhospitable empty and windswept paths were often a detour and raised many questions concerning firefighting, maintenance and orientation. London had always been a city where old and small alleys reigned, and it appeared that this would not change easily. Eventually, the pedway scheme became devoid of life and the ambitious plan ran into a dead end. Apart from a typological revolution, façades were reinvented too. New building methods and materials allowed for a complete rethinking of the façade, and exchanged the massive masonry walls for the light glass-andsteel curtain walls and concrete. Two architectural styles which made up the majority of this period’s developments can be distinguished here: a Bauhaus and International Style movement of stripped steel and glass facades (e.g. London Wall development, P&O Building, Commercial Union Building), and the massive, Le Corbusier-inspired concrete brutalism (e.g. Barbican Estate, Draper’s Gardens). The combination of this functionalist architecture and the failure of the pedway scheme, which was an intrinsic part of almost every office building of that period, soon caused the downfall of the first generation of high-rise buildings in the City. Also, technologies such as airconditioning and computer infrastructure weren’t taken into account at the time of their construction, rendering the buildings unsuitable fairly soon. Most buildings lasted for only two or three decades, after which they were heavily refurbished or demolished to make way for the next generation of office buildings. However, some landmarks of this period still remain as of today. The Aviva Tower (Commercial Union) with its double-height plant floors and Seagramlike piazza is one of the few examples of International Style architecture that are left in the City. In 2016, plans were revealed for a new, taller office tower that would replace the CU Building. III.

After the Big Bang: the horizontal skyscraper

As the sixties passed, it didn’t take long before another event caused a second building boom and revolution in high-rise architecture. 1986 was another turning point in the financial world, when a deregulation of financial services took place under Margaret Thatcher’s government. This event, referred to as the ‘Big Bang’, brought new rules into force, which allowed more foreign banks to start their business in the City. (Hamnett, 2003) This, of course, required the provision of more office space. Along with the deregulations came important technological improvements which made the existing office stock largely unsuitable for two reasons. Firstly, the arrival of computers, the need for data storage and the introduction of airconditioning required a larger floorto-ceiling height. Secondly, large open-plan trading floors were required to meet the needs of the banks (Lenon, 1987). Most existing buildings could not meet these new demands, so in the following years, a new building typology emerged: the groundscraper. These vast, compact buildings were designed to house large trading floors, and could provide enough office space to harbor


“The greatest failing of many ‘iconic’ works of architecture is that they are essentially one-liners, the product of a clever, even brilliant idea, but not thought through or refined or tested. The strength of 30 St Mary Axe is that it is anything but a one-liner. It is a complex, considered ,multivalent work of art.” Kenneth Powell. From: 30 St Mary Axe, A Tower for London.


some of the biggest companies, while at the same time allowing conservation areas to be protected. As these new buildings replaced many of the existing office buildings, many of whom were considered as failures, about half of the City’s office space was rebuilt in the decade following the Big Bang (Hibbert, Weinreb, Keay & Keay, 1983). The early wave of these bulky buildings were designed in a postmodernist fashion, reintroducing stone cladding and other traditional materials to the City’s architecture. Just like the sixties with its International Style architecture, there was a significant influence of these new groundscrapers from the United States. Postmodernism didn’t last long though, and by the 1990s, it had largely disappeared from the drawing board. At the same time, when recession struck the country, Canary Wharf emerged to the east of the City. This new economic centre at Isle of Dogs was an area upon which a rigid Manhattan-style grid was placed which formed a rival for the City’s leading role as the main financial centre. To keep up with its competitors, the City simply needed more office space. Unfortunately, it was still restricted to its boundaries, so horizontal extension was not an option. Ground prices kept rising as available plots started to become scarce, thus stimulating the construction of even higher towers. As offices became more strongly dependent on the quality of ICT systems, there was a continuous pressure for high-quality buildings which kept increasing in size and technical complexity. Around the turn of the millennium, the City had done everything it could to provide enough office space, by building groundscrapers of up to ten stories in height, filling in old railway lines or going as far as building over roads, as can be seen at Alban Gate, a postmodernist groundscraper which was built over a road. Eventually, most building sites were filled and building up seemed to be the only reasonable alternative. The idea of the groundscraper is still being applied in the City as of today, albeit very differently compared to the ones erected during its heyday after the Big Bang. The recently finished complex at 5 Broadgate is a display of the capabilities of the groundscraper concerning efficiency and communication in a building. IV.

After the Millennium: the sky has no limit

As its name suggests, there is no inexhaustible amount of space in the Square Mile. With office vacancy rates at an all time low1 (Grigorovsky, 2015), the urge to build tall is higher than ever. However, several constraints limit the maximum height of new buildings. The sum of the areas confined by protected views on St Paul’s Cathedral, protected views from the London Fire Monument and conservation areas leave only a small part of the City free of restrictions. Out of the ten highest built or permitted skyscrapers in the City, eight are located in what is called the Eastern Cluster in the Bishopsgate area. This is one of the few locations in the City where conservation areas have not completely impeded the construction of high-rise buildings, which brought about the area’s complete transformation to a high-rise building cluster since the construction of Richard Seifert’s Tower 42 was started in 1972. Surprisingly, it took more than twenty years after Tower 42 was finished, before a new skyscraper would be introduced in the City again. The need for wide trading floors that emerged with the Big Bang, simply demanded larger horizontal surfaces instead of vertically stacked office floors, for which the groundscraper was a logical solution. After this two-decade gap, the famous, gherkin-shaped (hence its more widely accepted nickname The Gherkin) Swiss Re Building appeared on the City’s skyline in 2003. Despite being controversial at an early stage, it quickly gained enormous public approval, and it would soon prove to be the development that made most Londoners familiar and comfortable with the sight of skyscrapers in the City. Despite countless attempts of certain media to portray the building as a failure, it was loved by most of the public and succeeded to overcome the resistance against tall buildings that emerged after the failure of the earlier high-rise experiments in the sixties and seventies. Its nickname, coined to describe the building’s unusual shape, set the trend of giving nicknames to the new skyscrapers, which also helped to gain public approval. The Gherkin, with its highly advanced technological design in terms of climate control and its innovative facade, had set high standard for what was yet to come. However, the near future may show a different evolution due to the recent Brexit referendum. It is likely that the recent Brexit will cause many big companies, including some of the big banks which currently occupy a large part of the City’s office space, to leave the UK (Gandel, 2016). 1


“Leaning out as it climbs to 34 storeys, the concave shape of the building's southern elevation is described by Viñoly as a deferential "bow" towards the river. That the curvaceous curtain wall has the simultaneous effect of converging the sun's rays into a magnified beam of heat, capable of melting cars, might be seen to be a fluke byproduct of this architectural flourish, an unfortunate consequence you could never predict.” Architecture critic Oliver Wainwright talking about the failure of 20 Fenchurch Street. From: The Guardian.


With new tall buildings appearing in the City with varying success, more parties started to voice their concerns about the rising skyline (Weiss, 2015). For decades, the Prince of Wales has been a conservative protector of the City’s historic skyline, and in March 2014, a Skyline Campaign was established, backed by more than eighty public figures (Weiss, 2016). The campaign criticizes the hollow statements of the City’s policy, which state that tall buildings are acceptable if they are ‘well-designed and in the right place’ (Moore, 2016). It is easy to question the meaning of these values if we look at some recent additions to the skyline. One of the latest skyscrapers, the ‘Walkie-Talkie’ at 20 Fenchurch Street, nicknamed for its resemblance to a Swedish 1960s telephone (Rees, 2015), was considered an utter failure in terms of both values. It is despised by English Heritage and Unesco and recently won the Carbuncle Cup as the UK’s worst building of 2015 (Wainwright, 2015). To begin with, its concave façade with its reflective glass focuses the sun’s rays, causing extreme temperatures at street level and melting cars (Lallanilla, 2013). Secondly, that same façade caused strong downdraughts: as wind hits the building, it is guided downward, creating a wind tunnel effect at ground level. While these practical problems could be resolved with sun shades and canopies, the building’s very location and its bulky mass are less surmountable issues. The City’s policy was to build skyscrapers in a tight cluster in between the Swiss Re Building and Tower 42. When the Walkie-Talkie appeared right outside the cluster, this inconsistency was heavily criticized. Peter Rees, the Corporation’s former Chief Planning Officer, defended this, saying that the building was to be like the ‘figurehead at the prow of a ship’ (Wainwright, 2012), from where the rest of the tall building cluster and the City could be admired. The promise of a free public garden on the upper three floors was a convincing element to approve the tower, but what was promised to become a lush oasis of vegetation, ended up as a meagre yet hyper-expensive rooftop bar. Furthermore, it is rather doubtful that a space for which access must be arranged three days in advance using a complex online booking system, could be called anything near ‘public’. Other skyscrapers have publicly accessible spaces at the top as well, but most of them are exclusive venues. For an environment where face-to-face contact is essential, it is remarkable that some skyscrapers have such a lack of collective space at their bases. Other buildings, like the Leadenhall Building, have provided open spaces at ground level, and some of the planned developments seem to be more aware of this as well. Unfortunately, most of these ‘public spaces’ are POPS - or Privately Owned Public Spaces. Partly created as a response to terrorist attacks which damaged buildings in the City in the nineties, these supervized spaces are generally very well maintained - as they are in private hands - but often lack the ability to create a friendly, relaxed atmosphere. The City’s policy to keep buildings inside a cluster, has both advantages and disadvantages. As mentioned before, it was a natural result of getting as much density as possible while staying out of conservation areas. Secondly, it is this very densification of businesses, where office workers have everything they need inside a very small radius, that makes the cluster so successful. Another point is sustainability: clustering tall buildings can be an advantage in terms of transportation, energy efficiency and land use (Lyne, 2002). However, there are counter-arguments against the clustering of towers. The church spiredominated skyline of London before the building booms shows a City with many individual, clearly defined landmarks. When all these new skyscrapers, irrespective of their architectural quality, are placed in a tight cluster, little remains of the individual perception of these towers. The towers, designed as separate objects, risk becoming part of a homogeneous amalgam of steel and glass as most of them have façades with similar materials. From another point of view, this can be seen as an advantage, as hiding towers in the middle of a cluster can actually limit the total impact on the skyline. Another issue is that, when all towers are placed together, their individual virtue of casting long but narrow shadows is no longer valid. Between the planned skyscrapers of 6-8 Bishopsgate and 22 Bishopsgate, there is a fourty-storey canyon, measuring just three meters wide (Wainwright, Ulmanu, 2015). The experience of walking through this enormous canyon might vary signifcantly


“There’s a real psychology of proximity in the cluster. The insurance industry, more than anything else, relies on face-to-face contact. There’s a culture of huddling together for collective benefit.“ Richard Rogers talking about the cluster of office towers in the City.


depending on the observer’s preference. Like with every flaw, defenders of the development claim that the fact that these two buildings almost touch, represents the way the insurance industry relies on face-to-face contact (Wainwright, Ulmanu, 2015). The clustering was also a result of a policy to protect important views on existing landmarks. For quite some time, one of the major concerns was the conservation of some views on St Paul’s. A series of what is called ‘Fixed Panoramas’, ‘Linear Views’ and ‘River Prospects’ (Greater London Authority, 2012) was established by the London View Management Framework, which would help to protect important viewing corridors. However, it must be noted that even these corridors are subject to change, as the narrowing of a viewing corridor in 2005 proves (Glynne, Hackney, Minton, 2009). This last fact shows once again that the City, with its laws that lasted for almost a thousand years, miraculously manages to apply rules which can be changed at any time. What may be called a lack of rules, is what enables the City to be much more dynamic than cities like Paris, where strict street patterns have completely inhibited any changes. Like no other place, the City is a place where ‘form follows finance’. A quick look at the current conservation areas shows how some of these areas are threatened by planned developments. The rate of renewal may vary as the economy changes, but the multitude of planned projects in the near future on the timeline shows how much is about to change in the City. However, it seems that 2015 might be another turning point in London’s skyline transformation. Eric Parry’s 1 Undershaft project was approved this fall and with a height of 304 meters, it equals the height limit imposed by the Civil Aviation Authority. Building any higher might be dangerous for aircraft approaching or leaving the nearby airport. Therefore it seems unlikely that this limit will soon be increased. V. Conclusion: looking up, looking ahead When this text was first written at the end of 2015, it appeared that -given the height restriction imposed by the CAA and conservation bodies- the eastern office cluster in the City had approached its maximum size. Only a few months later, a new report stated that new plans are being considered to extend the office cluster towards the loathed 20 Fenchurch Street building (City of London Planners, 2016). The official reason for this extension of the cluster is that this would decrease the visual impact of the currently isolated 20 Fenchurch building, but obviously the need for more office space plays a role that should not be neglected. Again, this goes to show how quickly things can change in the City of London. In the last decades, the City has attempted to build an ambitious street in the air scheme, constructed vast machines for business and designed skyscrapers in the middle of medieval streets. The success of all these is varied, and together with the lack of space, we must think carefully about what we design. The wacky shapes of some recent skyscrapers might draw plenty of attention, but they do not represent the efficiency that is desirable for large companies that have their headquarters inside. While the vanity height2 of London’s skyscraper is still reasonably small, it is clear that the iconic spires of its skyscrapers attach great importance to showing who’s got the tallest of them all. After all, things haven’t changed all that much after many centuries in the City of London.

The term vanity height is usually used for supertall buildings only (which would not be applicable to the skyscrapers in London, as they measure less than the required 300 meters) to describe “the distance between its highest occupiable floor and its architectural top”, as described by the Council on Tall Buildings and Urban Habitat. In other continents, mostly in large cities in China, the USA and UAE, this phenomenon is striking in the high-rise architecture, as most skyscrapers have enormous spires. 2



View of the City of London as of today, including the planned highrise buildings in the eastern cluster



Concerned about the views from and towards some important landmarks, the City introduced several overlapping zones in which strict limitations control the height of new buildings. St Paul’s Cathedral is the most determining factor in this respect, along with the Great Fire Monument and the Tower of London. In 1938, the City introduced a policy named “St. Paul’s heights”, to guarantee that the cathedral would remain visible from important viewpoints. To make sure that visitors of the Great Fire Monument would have a clear view towards the Thames, a local policy limits building heights around Monument. On a larger scale, important viewing corridors across the City were to be maintained. To achieve this, the London Plan introduced the London View Management Framework. This document contains a set of wedge-shaped viewing corridors, often originating in parks or important elevated places outside the City, which point towards St. Paul’s Cathedral and Westminster Abbey.

Other guidelines protect views from streets towards the cathedral, as well as the space behind it. These strict limitations have a clear influence on the City’s high-rise buildings. Broadgate Tower in the northeast office cluster of Broadgate, is shaped in such a way that it fits in between viewing corridors. Another example is the Leadenhall Building, whose shape was chosen as to reserve the sky behind St. Paul’s when approaching it on Fleet Street. The summation of these specific areas shows an interesting figure: Only two main areas lie outside the viewing corridors. In the north lies a wide wedge, where the office clusters of Broadgate and London Wall are, as well as the high-rise towers of the Barbican Estate. A new proposition for a timber skyscraper of eighty stories suggests that more highrises will appear in this area. Secondly, the eastern office cluster grew at an extraordinary speed in the last decades. Currently, this cluster is dotted with building sites, most of them announcing the rise of yet another skyscraper. 26



City churches Pre-war buildings Post-war building boom Big Bang After 2000 Planned developments 27


THREE TRIPTYCHS Timeline showing the parallel evolution of highrise architecture in the City, together with important political, economical, historical and city planning events. During my research, I gradually started to discern several waves of new building typologies that changed the face of the City’s skyline. In this part, three triptychs will give an extended view of the changes in the City in terms of its high-rise architecture. The particular division of the timeline in three parts was made possible because of the rather clear separation of building waves. The first part starts at the Great Fire of London of 1666, which is the start of a fascinating building boom of churches designed by Sir Christopher Wren. In a period of about half a century, dozens of churches were rebuilt in a wide variety of styles, including gothic, romanesque and classicist influences. This first wave was topped off by the new dome of a new St. Paul’s Cathedral, which would continue to be the largest structure in the City for several more centuries. The second part starts at the beginning of the 20th century, after the Great War destroys large parts of the City. For several decades after the First World War, hardly any high-rise architecture appears. Only in the 1960s after another devastating war, an office boom brings about the construction of many office towers in the area around London Wall, Barbican and the Eastern Cluster. This era is characterized by the modernist podium-and-tower typology and brutalism architecture. A third part shows the gradual change from the groundscraper typology, characterized by large trading floors and post-modernist architecture, towards the skyscraper typology that now dominates the City skyline. After the timeline, a catalogue provides a clear overview of the buildings that appear in the timeline.



1670 168 THE BLACK DEATH City population: 306.000

1066: William of Normandy lands on English soil with his army and defeats King Harold and his army, after which he is crowned King of England. William the Conqueror City population: 18.000

One of the biggest fires London has ever seen consumes the majority of the City. Miraculously, there were almost no casualties, but the devastation was colossal. Old St Paul’s Cathedral was destroyed, as well as most of the city within the walls. The fire lasted for days, but was stopped from spreading any further eventually by destroying rows of houses. Many churches fell to the flames.


CITY PLANNING 1667: London Rebuilding Act: measures were taken to decrease the risk of fire in the future. Height standards were set for the first time, which varied according to the width of streets, wooden houses are forbidden, as well as over-hanging upper storeys.

WREN’S LONDON Only about one month after the destructive fire, Christopher Wren comes with a plan to rebuild the City in a completely different, organised way. The plan, with its long straight avenues and piazzas was clearly inspired by Sixtus V’s work in Rome, but the plan was never accepted as Londoners started rebuilding their buildings on their old plots. Wren is appointed, together with Dr R. Hooke and E. Woodroffe, to rebuild the City’s churches.

Sir Christopher Wren

ARCHITECTURE & TECHNOLOGY Over one hundred parish churches are spread out over the City. Even these relatively short towers and steeples clearly stick out of the skyline.

Rococo After some parishes in the City are merged, only 52 out of 87 parish churches had to be rebuilt by Wren and his team in about 50 years. The churches are a collection of many different architectural styles. Wren supervised most of the work, but stated that the “Order is the workmen’s own invention.” As the medieval predecessors of the churches had hardly any street facade (as they were built between crowded houses), and these houses were rebuilt after the Fire, the new churches didn’t need special facades. Most work was put in the steeples, which differed not only in shaped but also in used materials, thus creating a fascinating skyline.


1440 Guildhall 27m

St Stephen Walbrook

St Edmund King & Martyr

St Swithin London Stone

Fire Monument

St George Botolph Lane


St Mary at Hill

1660 1670 168 St Brides


1240 Old St Paul’s

St Christopher le Stocks

1098 White Tower

80 1690 1700

Allhallows the Great

St Peter Cornhill

St Margaret Lothbury

St Dionis Backchurch

St Margaret Pattens

St Clement Eastcheap

St Michael Crooked Lane

St Austin Watling Street

St Benet Paul’s WHarf

St Alban Wood Street

St James Garlyckhite

Allhallows the Great

Christchurch Greyfriars

St Giles Cripplegate

St Michael Queenhithe

St Mary Aldermary

St Nicholas Cole Abbey

St Mary Abchurch

St Martin Ludgate

St Mary le Bow

St Anne St Agnes

St Olave Old Jewry


St Dunstan in the East

St Allhallows Bread Street

St Vedast Foster Lane

St Andrew Holborn

St Mary Somerset

St Mary at Hill

St Mary at Hill

St Mary at Hill

St Lawrence Jewry

80 1690 1700

WREN’S SPIRES City population: 208.000

By the end of the 1600s, the City has become the commercial centre of gravity of the British empire. Bank of England, the Stock Exchange and many insurance companies are entering the CIty, exerting a strong centripetal influence on companies towards the City.


1710 1720

1700s: As London expands outside the City, the resident population starts to diminish. This allows for more intensive land use and an economy that is more based on commercial activities.

1712: Christopher Wren’s masterpiece, St. Paul’s Cathedral is finished, marking the end of a 40-year reconstruction period of churches in the City. The building would dominate the City’s skyline for the following centuries.

St Paul’s Cathedral

St Magnus the Martyr

1710 1720 32

1920 1930 19 HISTORY

World War I

City population: 19.564


1925: New York overtakes London as the world’s largest city.

CITY PLANNING 1890: Queen Anne’s Mansions controversy following the construction of the 160 feet-tall Queen Anne’s Mansions in Westminster causes city planners to limit building heights more strictly.

1938: in order to protect important views on St Paul’s Cathedral, the City of London Corporation introduces height restrictions, which depend on street width.

1930: London Building Act raises the maximum height of buildings from 80ft to 100ft. The limiting factor was the length of the ladders of the Fire Brigade.

1894: London Building Act The height limit on all London buildings of 100 feet. 80 feet to the cornice, and an additional 20 feet for a recessed roof, is set.

1934: Royal Fine Arts Commision protecting views on St. Paul’s and the area around the cathedral. William Holford


Neoclassicism Art Nouveau

Art Deco During the inter-war years, new technologies from the USA bring about great changes in financial and business services. Automation helps transform the counting house-type of office to the modern office building.

Beaux Arts Neo-gothic


Peterborough Court

Adelaide House

1920 1930 19 10 Trinity Square

Central Criminal Court

International Style


940 1950 1960

World War II 1940: London Blitz German air raids destroy large parts of the City. 30% Of the City’s office space is destroyed.

City population: 7.568

1950s: London is slowly recovering from the War. Housing and schools get first priority for the rebuilding plans, but the need to modernize Britain to keep up with the pace of the USA and the need for the City to secure its position as a financial centre, pushes the start of office developments. In the City, offices are almost the only type of building being erected at the time.

1956: Conservative government introduces higher subsidies for higher buildings.

1960s: While most banks keep their tradi many office buildings are adapting an Am

1947: 3rd schedule of Town & Country Planning Act: permits existing buildings to be enlarged by up to 10% without permission or incurring tax.

1946: After the destruction caused by German bombings during World War II, Charles Holden and William Holford were appointed to design a plan to reconstruct the City, as large swathes of it were left empty after the War. In their interim report, their focus was to design the City as a global fnancial and commercial centre, where pedestrian and motorized flows were separated, and to take into account the need to conserve important sightlines for St Paul’s. Diversification of the City and its buildings were also

Charles Holden

1943: County of London Plan Foreshaw and Abercrombie encourage building higher in certain, well-located sites. Out of fear that well-located sites will be developed at uniform maximum heights, they suggest placing ‘well-sited tall buildings’ on certain nodes.

1951: Morrison, the Minister of town and country planning approves a declaratory order for the majority of the City of London Plan, made by Holden & Holford. This allowed rapid rebuilding of the City’s office space.

1956: LCC Town Planning Committee publishes guidelines for high buildings in London, and the LCC is freed from height constraints.

1949: to limit public expenditures, the government stimulates the building of cheap and quickly-built office buildings, called ‘lessor schemes’. The lack of architectural quality caused reactions very soon. There was a clear contrast between these buildings and those, built by companies on their own account, as to better represent their company.

Modernism 1944: Abercrombie Plan: a visionary plan to rebuild large parts of the City after the War.

1948: Ministry of Town & Country Planning introduction of plot ratios: in the City and West End, plot ratios of 5:1 are allowed, with a slight increase of 5,5:1 around Bank.

Brutalism By the start of the Second World War, seventeen of Wren’s churches had already disappeared as some churches stood on sites that were redeveloped or at streets that were widened. By the end of it, most churches were heavily damaged by incendiary bombs from German air raids.

1950s: Heavier equipment becomes available for construction

1955: Turn Again exhibition by MARS questions the state of London’s office buildings and the lowered architectural standards..

Lee House


St Alphage House

Bucklesbury House


Fountain House

Atlantic House

940 1950 1960


1970 1980

1971: An IRA bomb explodes on the 33rd floor of the BT Tower. There were no casualties, but there was extensive damage caused to

1970s: more international banks arrive in the City.

1970s: financial and business services dominate the City in terms of office eployment, accounting for 55% of all employment in 1970, to 89% by 2005.

itional architectural style, merican design.

1979: Margaret Thatcher is elected Prime Minister of the UK.

1973: Oil crisis

Margaret Thatcher

1965: the London County Council is replaced by the Greater London Council. 1969: the GLC introduces three types of zones to distinguish locations where tall buildings are apporpriate. The policy disappeared in 1986. 1964: The Night of the Long Pens an announced ban on new office buildings in London causes developers to arrange as many deals the night before the ban becomes active.

6-8 Bishopsgate

Milton House

Shakespeare Tiower

One Angel Court

Cromwell Tower

Petticoat Tower

Dashwood House

Cromwell Tower

99 Bishopsgate


Bastion House

Stock Exchange Tower

International Press Centre

Limebank Tower

Aviva Tower

P&O Building

20 Fenchurch Street

Britannic House

Drapers Gardens

City Tower

1970 1980

NatWest Tower

1980s: Tall buildings seem to be out of fashion. This is probably the cause of the failure of residential towers of the last decades.


1990 2000 HISTORY

REES’ SKYSC 1993: An IRA truck bomb explodes in the Bishopsgate area, destroying the majority of the Baltic Exchange building, as well as damaging many adjacent buildings such as 99 Bishopsgate and the Aviva (St Helen’s or Commercial Union) Building. One person died.

ECONOMY & POLITICS 1986: Big Bang: deregulation of the financial markets under Margaret Thatcher. This caused a revolution in office building in the City. Even more banks enter the City. These banks stimulated the development of new office buildings as they required open offices floors and open facades for more natural light.

1990s Recession; Property prices fall dramatically due to recession across the globe, which causes an oversupply of office space.

1999: the Greater London Authority is created.

1987: Stock market crash

CITY PLANNING 1985: Peter Wynne Rees is appointed Chief Planning Officer for the City of London Corporation. In the next 29 years, he will have an enormous influence in the process of the City’s transformation to a high-rise city. His belief is that skyscrapers must only be built when there is no other option. As the City was running out of space at the turn of the millenium, the City had to build higher as an alternative to the bulky groundscrapers of the nineties.

late 1980s: creation of a new business district of 10 million square feet at Canary Wharf, providing plots with plot ratios of 12:1.

1999: office availability in Central London is halved in four years. To make sure rents don’t keep rising, more office space is needed.

1995: seven years after the Big Bang, almost 50% of the City’s office space has been modernised.

Peter Wynne Rees 1986: To meet the demand of the new banks settling in the City, the City of London Corporation relaxes development controls, causing a dramatic increase in planning permissions.


Technical innovation in buildings brings new systems like raised floors, suspended ceilings and steel frames.

Hi-tech architecture Post-modernism


88 Wood Street

Lombard Street

Alban Gate

200 Aldersgate

Millennium Tower

1 America Square

1 Minster Court

Britannic House

Peterborough Court


175 Bishopsgate

Beaufort House

Lloyd’s Building

Northern & Shell Building

Natwest Tower

1980 1990 2000 6-8 Bishopsgate

Milton House

One Angel Court

1986:: Groundscrapers can meet the needs of banks by providing large open trading floors.

2010 2020


City population: 8.100

2000: Ken Livingstone becomes the first Mayor of London. Although he used to be against tall building in the City, he recognized the need for highrise office buildings in order to compete with other important economic centres like Frankfurt and New York City. He later became a leader of a pro-highrise lobby and had a large influence on the arrival of highrise buildings in London.

2008: Boris Johnson becomes Mayor of London. At the time of his election, Johnson showed concerns for the consequences of highrise buildings on London’s heritage. Just like his predecessor Livingstone, his opinion changed gradually towards a more prohighrise view.

2001: In ‘Towards the London Plan’, Ken Livingstone states that ‘High buildings are often flagship developments that play an important part in regeneration.’ Ken Livingstone

2016: Brexit the United Kingdom leaves the European Union following the United Kingdom European Union membership referendum. Without doubt, this will influence the property and investment market in the City. Worries arise that large banks will leave the country.

Boris Johnson

2016: City of London planners consider the possibility of extending the existing eastern high-rise cluster to the south. This way, the walkie-talkie shaped 20 Fenchurch Street Building would attract less negative attention, according to the planners.

2000: deputy Prime Minister John Prescott grants planning permission for a new building for insurance company Swiss Re, the first tall building in the City in 20 years.

2001: After a public enquiry, the Heron tower gains planning approval, once again raising the building height limit in the City.

2000s: the nicknaming of new towers helps to gain approval from the general public.

6-8 Bishopsgate

40 Leadenhall Street

22 Bishopsgate (canceled)

22 Bishopsgate

100 Bishopsgate

5 Broadgate

20 Fenchurch Street

5 Moor Lane

6 Bevis Marks


122 Leadenhall Street

St Botolph Building

Heron Tower

New Court

Broadgate Tower

Willis Building

6 New Street Square

5 Aldermanbury Square

Drapers Gardens

Minerva Building

1 Plantation Place

60 Fenchurch Street

30 ST Mary Axe

Moor House

58 Fenchurch Street

2010 2020

2030 2040

The height limit of 305 meter, established by the Civil Aviation Authority for the safety of low-flying planes, is reached. No building in London is allowed to be higher than this.

Barbican tower

120 Fenchurch Srreet

12-14 New Fetter Lane

London Wall Place

1 New Street Square

1 Undershaft

Principal Tower

Contextual Skyscraper

London Wall Place

60-70 St Mary Axe

52-54 Lime Street

2030 2040 38

1098 White Tower

1087-1666 Old St. Paul’s Cathedral

Architect unknown 27m

Architect unknown 149m

1686 St Lawrence, Jewry

1951-? Atlantic House

Christopher Wren 39,6m

Bennett & Son

1985 Northern & Shell Building Covell, Matthew & Partners 43m

2011 New Court

OMA & Allies & Morrison 70m

1440 Guildhall

1671-1782 St Christopher le Stocks

1672 St Michael Cornhill Sir Christopher Wren

John Croxton 27m

Sir Christopher Wren 24m

1686 St Mary Abchurch

1686 St Michael Queenhithe

1687 Christ Church Greyfriars

1687 St Michael Crooked Lane

1957-1999 Memorial Building

1958 Fountain House

1958-2011 Bucklersbury House

1961-2001 Moor House

Christopher Wren 42,6m

Ronald Ward & Partners 50,6m

1986 Lloyds Building Richard Rogers 84m

2011 St Botolph Building Grimshaw Architects 59m

Christopher Wren 41m

W. H. Rogers 47m

1989 Beaufort House RHWL Architects 63m

2011 Heron Tower (110 Bishopgate) KPF Associates 230m


Sir Christopher Wren 30m

Christopher Wren 49m

Campbell-Jones &Sons

1675 (top 1703) St Brides Christopher Wren 69m

1687 St Clement Eastcheap Christopher Wren 26,2m

1676 St Mary-At-Hill Christopher Wren 29m

1687 St Alban Wood Street Christopher Wren 28m

1676-1904 St George Botolph Lane Christopher Wren 26m

1687 St Austin Watling Street Christopher Wren 44,2m

1962-2014 St Alphage House 2 Fore Street

1962-1990 Lee House 125 London Wall

1964 City Tower 40 Basinghall Street


120 London Wall Lewis Solomon, Kaye & Partners 67,4m

1990 175 Bishopsgate

1991 Peterborough Court

1991 1 Minster Court

1992 200 Aldersgate

KPF 64,2m renovation

GMW Architects 74m

1991 1 America Square

2013 122 Leadenhall Street

2013 6 Bevis Marks

2013 5 Moor Lane (Heron)

2014 20 Fenchurch Street

2014 Approved 40 Leadenhall Street

Skidmore, Owings & Merrill 64,8m

Rogers Stirk Harbour + Partners 225m

FLethcer Priest Architects 72m


Maurice Sanders Associates 68,9m

David Walker Architects 112m

John Burnet Tair & Partners 65m

RHWL Architects 63,7m

Rafael ViĂąoly 160m

John Burnet Tair & Partners 69,2m

Fitzroy Robinson & Partners 90,8m

MAKE Architects 170m

A CATALOGUE Overview of the City’s high-rise architecture

1677 Great Fire Monument

Christopher Wren & Robert Hooke 61m

1687 St Margaret Pattens Christopher Wren 60m

1967-1990 Britannic House 1 Ropemaker Street F. Milton Cashmore 122m

1992 Alban Gate (125 London Wall) Terry Farrell 82m

2015 5 Broadgate Make Architects 69m

1678-1962 St Swithin, London Stone Sir Christopher Wren 45m

1687 St Clement

Sir Christopher Wren 26m

1967-2007 Drapers Gardens Richard Seifert 100m

1992 54 Lombard Street GMW Architects 87m

2015 Under construction 100 Bishopsgate

Allies Morrison Woods Bagot 172m

1679 St Edmund, King & Martyr Christopher Wren 27m

1679 St Stephen Walbrook Christopher Wren 40m

1679 St Olave Old Jewry

1680 St Anne & St Agnes

1680 St Mary le Bow

1695 St Andrew by-the-Wardrobe

1694 Allhallows Lombard Street

1969-1998 Limebank tower

1972-2014 International Press Centre

Sir Christopher Wren 27m

1690 St Margaret Lothbury

1694 St Michael Paternoster Royal

1694 St Mary Somerset

1968-2008 20 Fenchurch Street

1969-2008 P&O Building

1969 Aviva Tower (St. Helen’s)

Christopher Wren 42,6m

CLRP Architects 91m

1999 88 Wood Street Richard Rogers 75m

2015 Under construction 22 Bishopsgate Kohn Pedersen Fox 288

Christopher Wren 27m

Gollins Melvin Ward & Partners 54m

2000 Citypoint (Britannic House) 1 Ropemaker Street Sheppard Robson Int. 127,1m

2019 Canceled 22 Bishopsgate (Pinnacle) Kohn Pedersen Fox 278m

Sir Christopher Wren 37m

Gollins Melvin Ward & Partners 118m

2003 58 Fenchurch Street KPF Associates 62m

2015 Approved 6-8 Bishopsgate Wilkinson Eyre 168m


Christopher Wren 25,6m

Christopher Wren 26m

Howard Fairbairn & Partners 93m

2003 proposal Minerva Building

Nicholas Grimshaw Architects 217m

2015 Under Construction 60-70 St Mary Axe Foggo Associates 90m

Christopher Wren 68m

Sir Christopher Wren 26m

Richard Seifert 60m

1681 St Nicholas Cole Abbey Christopher Wren 41m

1695 St Andrew Holborn Christopher Wren 33,5m

1972 Stock Exchange Tower Fitzroy Robinson 100m renovated in 2009

2004 Moor House

2004 30 St Mary Axe (Gherkin)

proposal Contextual Skyscraper

2018 Under construction 52-54 Lime Street (Scalpel)

Foster & Partners 81,4m

Avery Associates 270m

Foster & Partners 179m

Kohn Pedersen Fox 190m

1682 St Mary Aldermary Christopher Wren 41m

1697 St Vedast Foster La Christopher Wren 27,4m

1976 Bastion House 140 London Wall

Philip Powell & Hidalgo M 68,5m

2004 60 Fenchurch Stre John McAslan + Partners 50m

2015 Approved Heron Plaza PLP Architecture 135,3m


1682 St Giles Cripplegate

1683 St James Garlyckhite

1683 St Benet Paul’s Wharf

1683-1941 St Mildred Bread Street

1684 St Martin Ludgate

1684-1878 St Dionis Backchurch

1684 St Peter, Cornhill

Christopher Wren 27m

Christopher Wren 42m


1698-1878 Allhallows Bread Street

1701 St Dunstan in the East

1711 St Paul’s Cathedral

1907 Central Criminal Court

1925 Adelaide House

1930 Peterborough Court

Christopher Wren 111m

E.W. Mountford 66,6m

1922 10 Trinity Square


Sir Christopher Wren 23m

1704 St Magnus the Martyr

1976 99 Bishopsgate

1976 Barbican Towers

1976 Dashwood House

1977 Petticoat Tower

1980 One Angel Court

1981 Milton House

1981 NatWest Tower (Tower 42)

1982 6-8 Bishopsgate

2004 1 Plantation Place

2007 5 Aldermansbury Square

2008 Willis Building

2008 6 New Street Square

2008 Drapers Gardens

2009 Broadgate Tower

2004 1 Plantation Place

2009 Ropemaker Place



Sir Christopher Wren 37m

Sir Christopher Wren

GMW Architects 104m

Arup Group 73m

2015 Approved 1 New Street Square Robin Partington Architects 70,5m

Christopher Wren 27m

Chamberlin, Powell & Bon 123m

Eric Parry Architects 71m

2015 Approved 12 Throgmorton Avenue Foggo Associates 73,4m

Christopher Wren 36m

Christopher Wren 56m

Fletcher Priest Architects 73,4m

Foster & Partners 125m

2015 Construction 1 Mitre Square Sheppard Robson 80m

Sir Christopher Wren

B.J. Brown 68,3m

Bennetts Associates 76,1m

2015 Approved London Wall Place Make Architects 76,9m

Christopher Wren 51m

Fitzroy Robinson & Partners 101m

Foggo Associates 74m

2015 Approved 120 Fenchurch Street Eric Parry Architects 68,8m


Thomas Edwin Cooper 51m

Sheppard Robson 66,4m

Skidmore, Owings & Merrill 165m

John Burnet, Tal & Partners 45m

Richard Seifert 183m

Arup Associates 73,4m

1684-1964 Allhallows the Great Sir Christopher Wren 26m

Elcock & Sutcliffe 63m

GMW Architects 88m

Arup Associates 95,6m


BUILDING REFERENCE Leadenhall Building, 122 Leadenhall Street Rogers Stirk Harbours & Partners


The Leadenhall Building is an impressive work of architecture in many ways. It is easily recognized from miles away because of its tapered profile, a consequence of a design decision that would safeguard protected views on St Paul’s Cathedral when seen from Fleet Street. Taking a closer look at it reveals some ingenious features on smaller scales. While tall buildings get recognized by the general public because of their iconic silhouette in the skyline, it is mainly their relationship with their direct surroundings at ground level that determines their success in the city fabric. Unfortunately, many of the recent additions to the City skyline contribute little to the public realm. With a gesture similar to that of the celebrated Seagram Building in New York, the Leadenhall Building opens up a large chunk of its first five levels to the public with an enormous outdoor space with a height of a staggering 28 meters, high enough to shelter the White Tower of London. Contrary to Mies’ clear rectangular void, the space’s edges are articulated by megaframes, steel bracing structures that envelope the entire building, and by the cantilevered floors that extend outwards as we go further up. By using this steel exoskeleton, the building has no need for a concrete core like those in traditional skyscrapers. The result is an impressive spatial configuration with the scale of a modern cathedral, where functional building elements succeed to create a space that expresses a sense of power. By providing this open space, the Leadenhall Building enables views across its site. Although this is meant as a gesture toward the adjacent buildings, some of these structures that once stood tall in the medieval City, such as the 12th century St Andrew’s Undershaft church and Lutyens’ Midland Bank, now look tiny as they easily fit in the colossal space under the 224-meter tall skyscraper. Despite its enormous scale, great emphasis has been put on the design of the nodes of the bracing system. Its enormous components have been manufactured off-site, making the building one of the largest prefabricated buildings ever. Each of the architectural elements resembles in one way or another a modern version of a gothic architectural vocabulary. Double H-profiled bracing columns keep the building stable like modern flying buttresses, and megabolts hold together the enormous columns while providing a level of detail to them like a reinterpretation of the gothic compound pier. A transparent ten meter long cantilevered structure, providing protection against unavoidable downward winds, causes a play of light and shadows on the floor of the outdoor space. On a larger scale, the building is located in the organic medieval fabric of narrow, curved streets, and reacts to this situation by making a passage through the ground floor towards Undershaft, one of the oldest cul-de-sac streets in the Central Business District of the City. These small streets connect the building with some other existing and planned highrise office buildings. These traffic-free paths offer a big opportunity for the office developments to have a pedestrian-friendly hub, not only during business hours but also in the evening. Despite the unquestionable architectural value of the giant open space, one could criticize what little remains of the actual public space because of the particular character of its exploitation. When trying to ascend the escalators in casual clothing, security guards quickly approach to make sure the area remains solely the territory for those who are dressed properly. Clearly, the privately-owned public space, often referred to as ‘POPS’, isn’t meant for everyone. Aside from some small shops at ground level, the building contains no public functions. Out of the impressive twenty-eight meters of public space, only the ground level can be used by the public. Despite this rather unfortunate reality, the space beneath Leadenhall Building remains an extraordinary place.








The building is located in the center of the eastern office cluster in the City of London. Right in between two existing landmark buildings, the Leadenhall Building (Rogers Stirk Harbour & Partners) and 30 St Mary Axe (Foster & Partners), One Undershaft will be at the center of the tightly packed office cluster, where four more skyscrapers are being erected in its proximity as we speak. When looking beyond the state-of-the-art modern architecture, this part of the City was one of the only spots that was spared from the Great Fire of 1666, and harbours some of the only churches of the City which survived the fiery blaze. Two of these churches are direct neighbours of the building’s site: St Helen’s Bishopsgate to the north and St Andrew Undershaft to the east. Overshadowed by their enormous glassy neighbours, they are often overlooked, despite the fact that they contain a multitude of historical layers of many centuries. The site currently houses an International-Style, 118 meter tall office tower called St Helen’s. While its architectural importance in the City’s many layered building history is undeniable, the building has no interaction with the public whatsoever and the quickly-changing building technology and office environments have made it outdated with its typical façade and rather high average floor-to-ceiling height of more than 5m. While further investigation might point out that renovation of the building should take precedence over rebuilding, for the sake of experiment the site is chosen as a platea rasa, or a clean square where a new tower can join the ever-changing high-rise landscape of the City. Another justification for this decision is the fact that new plans for a redevelopment of this site were recently revealed. Positioned in the middle of the bending medieval streets, the site has a long history of which every street name is a reminder. The address name, Undershaft, is a cul-de-sac street which bends its way between the buildings. Its name is thought to have orginated from a medieval tradition where a maypole was placed on the streets each Spring. The space of this site was therefore located ‘under the shaft’, a suitable predecessor of the proposed tower’s shafts.


Map of the City of London, with the outline of One Undershaft in a lighter shade of grey.





High-rise buildings 1 22 Bishopsgate KPF Under construction 2 Tower 42 Richard Seifet 1979 3 100 Bishopsgate Allies and Morrison Planned

2 8 14

4 6-8 Bishopsgate Wilkinson-Eyre Planned 5 Leadenhall Building RSHP 2014 6 Lloyds of London Richard Rogers 1984


7 Willis Building Foster + Partners 2007

9 15

8 30 St Mary Axe Foster + Partners 2003 9 52-54 Lime Street KPF Under construction




10 99 Bishopsgate GMW Architects 1976 11 Heron Tower KPF 2011 12 6 Bevis Marks Fletcher Priest Architects 2013

17 Historically significant architecture

5 11

13 St Peter-upon-Cornhill Sir Christopher Wren 1684


14 St Ethelburgaâ&#x20AC;&#x2122;s Centre Architect unknown 1411 15 Gibson Hall John Gibson 1865 16 St Helenâ&#x20AC;&#x2122;s Bishopsgate Architect unknown <1210

12 6

17 Holland House HP Berlage 1916



18 St Andrew Undershaft Architect unknown 1532 19 Leadenhall Market Sir Horace Jones 1881




14 2 12 16



8 17





9 6




II. THREE THEMES Looking back, looking up

In the course of my research of the first semester, I developed a clearer image of the strengths and weaknesses of the City’s particular high-rise characteristics. While the neverending clash between conservation (both of physical buildings as well as viewing corridors) and modernization forces both sides to make compromises, it also creates a fascinating and vibrant city where tourism and commercial activity keep the public space lively both day and night. But while the City has some unparallelled qualities that make it the place it is today, the research revealed some flaws in the high-rise architecture that currently resides in the City. A Story of Storeys shows the downsides of both the post-war office towers and the postmodern groundscrapers, but even today there is much to criticize about the latest generation of office buildings. The following design experiments with these themes and offers an alternative to some of the current flaws that are currently present in the City. The first theme that is addressed in the One Undershaft proposal, is that of the skyline. While high-rise buildings are almost inevitable in order to meet the needs of the City’s businesses, their designers carry a large responsibility for an omnipresent object that will appear in the daily lives of thousands of people for decades. When the overall shape of these giants is not considered well, these buildings alter the City’s historic skyline for the next decades. Therefore, this proposal attempts to match the desire to preserve views with the need for large amounts of office space. Views of St Paul’s, viewlines from important streets and the view from the Thames towards the City are all considered. The second theme that is tackled in this proposal, is that of public space. The prevalence of privately owned public spaces - or POPS - in the City shows the absolute power of capital in the City and the abundant presence of security guards and metal detectors show the impact that terrorist attacks had on the City. On the other hand, the City, in contrast to artificial business centers such as Canary Wharf, is a place that never seems to lose its liveliness: the typical lifestyle of office workers brings the pub and club live on the streets every night, and tourism guides thousands of people through the City. By incorporating a public programme in the building, One Undershaft makes sure that not only the surrounding space, but the building itself is kept alive outside business hours. It will be a building that belongs in a City that never sleeps. By creating new public space both around and underneath the building, putting emphasis on hidden historic sites and joining spaces to those of neighbouring buildings, it creates a more welcoming place under its shafts. The final theme addresses the way in which typical office buildings are organized. With relatively small floor areas, skyscrapers often constrain social interaction to a single floor. On different levels, One Undershaft introduces alternative spaces to promote both formal and informal interaction in a wide variety of spaces, which takes shape in winter gardens, sky lobbies and amenities. These amenities are a response to the changing workstyles of the busy modern office worker: the nine-to-five workday is a thing of the past, and in their hasty lives, employees want to have everything close at hand. The result is an office building with a large emphasis on everything that is next to the office and that what makes the lives of employees more enjoyable yet productive.




Placing another pawn on the board

Rather than creating a tower with a blatant spire, the building’s overall shape was a result of different considerations of a functional and contextual nature. Learning from the flaws of other skyscrapers in the City, the tower took shape. By studying different models of completely different tower profiles at the early stage of the design process, a fitting shape for the given site could be derived. The abundance of wasted space in the sharp top of the Leadenhall building and the superfluous complexity of some of the newest proposals, which lead to whacky buildings with lots of cumbersome corners and curved edges, led to a straightforward profile where every floor gets the maximum amount of space. While this functional consideration creates a large amount of office space, the size of the floor plan was scaled in such a way that the tower profile, when seen in the skyline, has a limited visual impact. When seen from the Thames south of the City, where the skyline is looked at the most, the tower shows its narrow side. When looking at the tower pependicular to its wide side, the tower is either covered by the elegant profile of 30 St Mary Axe from the east or the new office cluster from the west. Starting from the upper half of the building, the building becomes slightly less wide, which is a result of the viewing corridor seen from Fleet Street facing east towards St Paul’s Cathedral. Where the Leadenhall Building gives way for this viewing line with its sloped profile, the setback at One Undershaft creates a similar gesture to make sure the sky behind St Paul’s isn’t covered by towers. Contrary to the bulky top mass of the Walkie-Talkie tower, One Undershaft adjusts its size as to minimize its visual impact. This way, the tower offers a compromise between creating as much office space as possible, while limiting the visual impact of the building on its far surroundings. The long but narrow floor plan of the building results in office spaces with a large amount of natural light, thus reducing the need for artificial lighting. The slender profile emphasizes the collective character of the winter gardens at the south side and elevator lobbies in the north façade. At night, the winter gardens remain lit to show the lush collective spaces of the office building to the public. On the north side, an elevator shaft which extends out of the façade reaches up all the way to the top of building, leading visitors and employees alike to the facilities at the top. Visitors who enter these elevators, will have a panoramic view through the structure as they go up in the fast elevators, while a play of light of the swiftly moving elevators can be observed from afar. Again, this will show that the tower is not just a place for working, and will show that the City remains alive even at night.

Classic configuration

Squeeze tower to create slender silhouette and allow more light to enter building


Setback to safeguard St Paul’s Cathedral views


The view from one of the important roads that lead into the City, Aldgate High Steet. The tower is mostly hidden behind Fosterâ&#x20AC;&#x2122;s 30 St Mary Axe.

View from the north, one of the few views where most of the tower can be seen. Moving a little bit further counterclockwise on the map, the tower is hidden by the planned 22 Bishopsgate and Tower 42.

Another view from the north. Most of the tower is hidden behind the enormous 22 Bishopsgate tower.


The view from the west, from Fleet Street. This view shows the setbacks of both 52-54 Lime Street, the Leadenhall Building and One Undershaft, in order to preserve an open sky behind St Paulâ&#x20AC;&#x2122;s when seen from Fleet Street.

View from the Thames: the narrow profile of the tower is visible between the Leadenhall Building (left) and the 52-54 Lime Street tower which is currently under construction.

Seen from the east, the tower is only obstructed by lower buildings (not shown on model). Note however that the planned development of 40 Leadenhall Street will be placed exactly in front of Undershaft when see from this side. When all currently planned developments are finished, the wide side of Undershaft wonâ&#x20AC;&#x2122;t be visible entirely from afar any longer.


PUBLIC SPACE Under the Shaft

Throughout the City, many types of arcades create a distance from the street at ground level, while providing shelter from the London climate, which might ocassionally be slightly chilly. In One Undershaft, a tall arcade runs all the way along the eastern side of the building. Firstly, this creates a new, triangular public space to the east of the building. It also provides a canopy on top of the building entrance to shelter pedestrians from the typical downdrafts created by the tower. Thirdly, it provides a visual path when walking north towards the building entrance of the hidden medieval church to the north, St Helen’s Bishopsgate. Even though it is one of the oldest remaining churches in the City, it is obscured by the tall surrounding buildings. By providing this open passage, new views are created to lead pedestrians to this calm spot in the city fabric. On the south side of the building, another volume is removed from the building to create an outdoor room parallel to the covered area of 122 Leadenhall. The terrace provided on this side of the building is sunlit thanks to its southern orientation and high ceiling and is linked to the square to the south of it. Together with the public space under the Leadenhall Building, one large public square is articulated. Both One Undershaft and the Leadenhall Building create views on another important church at the site, St Andrew Undershaft. The north side of the building provides a public access to the lobby which leads to the top of the building. The eastern and southern orientation of the building’s main passages and public facilities are the result of the main pedestrian flows which pass along Leadenhall Street and St Mary Axe. The new squares at the east and south side offer some new types of public space in the sequence of public spaces shown in the scheme later on. Together, these public spaces offer a diverse range of public spaces, mainly connected by car-free passages. The west side of the building is used for services, and follows the organization of the other new skyscrapers which are all facing their service entrances towards this square in the middle of the building block. Deliveries can be made here without hindering the public space at the other sides of the building.

Public space at south side of site extends Leadenhall Building’s space

Reduce footprint to create south-oriented terrace


Create arcade as passage and to create views on St Helen Bishopsgate


Public space with very diffferent characteristics surround the site. upper left: existing square in front of One Undershaft, upper right: Leadenhall Market, lower left: space in front of St Helenâ&#x20AC;&#x2122;s Bishopsgate, lower right: space under Cheesegrater Building.




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New square in front of One Undershaft Square at Aviva Space under Cheesegrater

Passages under and around Lloyd’s Leadenhall Market

Lime Street Passage

St Margaret Pattens

20 Fenchurch Street

One Undershaft’s public spaces will be a part of a sequence of different alleys, squares and open spaces where pedestrians can walk freely with little or no car traffic.






lp oto


The office building, more than a ‘Machine à travailler’

When considering the busy lives of people working in the City, as well as the high requirements of the office buildings in one of the most expensive places to build in Europe, one would expect that an office building at such a location would provide more than mere office desks. It would be a pity if the building were only used during working hours by a very limited number of people, which is currently the case for many of the City’s office buildings. Therefore, One Undershaft is organized in such a way that it provides space for both commercial functions and public amenities to make sure the building becomes an important part of the City’s public space. In fact, the building is made up of two stacked office clusters, each connected to a couple of collective floors that provide services. Each cluster consists of eight units, again consisting of three office floors, adding up to a total of fourty-eight office floors for the building. Every three office floors are connected with a common winter garden, which provides an informal meeting place, reception area and location for conference rooms. Both office clusters have a sky lobby and amenities floor at their base, where employees of all companies can meet and make use of a wide range of amenities such as a fitness area, bars, cafeterias, lounges, showers and medical facilities. Both the bottom three and top two floors are accessible to the public, the former directly via the street, the latter via the elevators on the north side of the buidling. Both top and bottom of the building contain a restaurant, bars and event spaces, where the upper one has the advantage of offering beautiful views on the City. From the earliest coffee at the sky garden lounge, to a quick workout at noon in the fitness, up to the late night conference in one of the large conference halls, the building houses plenty of functions to make the long working days of employees as pleasant as possible.

Mechanical floors




Public Amenities Collective facilities



















Roof bar Mechanical floor Event space Unit 16 Unit 15 Unit 14 Unit 13

In an ordinary office building, getting from the front door to an office desk is a rather straight-forward task. In a building with over sixty floors and more than 7000 office workers, guiding everyone to their workspace smoothly is a Unit 11 more challenging task. Different types of elevators contribute to an efficient transportation system. On the following diagram, the infrastructure of the building is visualized as a continuation of London’s Underground network. Unit 12

Unit 10 Unit 9

Unit 8


The logic of using two stacked buildings that was mentioned earlier, enables a separation of the massive amount of people early on. Each one of these buildings consists of a sky lobby at its base, surrounded by amenities, and eight units of three office floors, totalling twenty-four office floors per ‘building’. While the northern core contains two series of Amenities Express Elevators 2 (Green and Yellow Line), which bring large amounts of people to a2limited Wintergarden Sky Lobby amount of floors (sky lobbies), the southern core brings people from the two Conference sky lobbies to their office floor (Blue Lines). Combined with an intelligent Mechanical floor Traffic Management System, a more efficient flow can be achieved.

The Traffic Management System distributes passengers of elevators Unit 7 more efficiently by calculating the quickest way to get everyone to their destination with the least amount of total waiting time. By providing every office worker with a badge, a simple scan of this badge at the office lobby Unit 6 will guide each person to their elevator. The system will group people in such a way that elevators don’t have to stop at an unnecessary high amount Unit 5 of floors. Visitors (clients, for example) are welcomed at the first level elevator lobby, where they must wait for their host to pick them up, or get access to a certain floor from the staff at the reception desk. Unit 4

At the northern end of the building are the Highline Elevators, which bring Unit 3 people straight to the top floor. These fast elevators are accessible from the ground floor and can be used both at night for public or private events and during business hours for business-related events at the penultimate event Unit 2 hall level. Unit 1

Finally, the Pink Lines show the possible trajectories of pedestrians through the building. The lower floors are easily reached on foot, as well as the sky lobbies, which are strongly connected to their amenities. All floors are provided with extra evacuation stairs, which are not shown on this scheme. Mechanical floor Amenities 1

Sky Lobby 1


Lecture hall Office lobby


Ground floor To Fenchurch Street Railway Station

To Liverpool Street Tube Station

To Bank Station

To Aldgate Tube Station

5 mins from Undershaft

4 mins from Undershaft

6 mins from Undershaft

5 mins from Undershaft

Key to lines and symbols Lower Express


Goods delivery

Upper Express

Lower Offices

Bicycle/motorcycle parking


Upper Offices

Elevator lobby



Nearby tube station


Rooftop Bar

Restaurant Event space Mechanical floor

Unit 16


Winter garden

Unit 15

Unit 14

Unit 13

Unit 12

Unit 11

Unit 10

Unit 9 Upper Amenities

Office elevators

Sky Lobby 2 Conference rooms Mechanical floor


Winter garden

Unit 8

Unit 7

Unit 6

Unit 5

Unit 4

Unit 3

Unit 2

Unit 1 Lower Amenities

Office elevators

Sky Lobby Lecture hall Mechanical floor

To Fenchurch Street Railway Station 5 mins from Undershaft

To Bank Station 6 mins from Undershaft

Restaurant Bar/CafĂŠ

Office lobby Ground floor


To Liverpool Street Tube Station 4 mins from Undershaft

To Aldgate Tube Station 5 mins from Undershaft

III. CONSTRUCTIVE ASPECTS An overview of One Undershaft’s structural aspects

STRUCTURAL SYSTEM In an early phase of the design process, the idea of two ‘hugging towers’ emerged as a response to the environment’s typical close proximity of skyscrapers. Instead of building two towers right next to each other, the idea was to turn this into one building with a stacked collective space (a winter garden) at their meeting point. Eventually, the design changed but the idea of the tower with two cores remained. Surrounded by some of the finest pieces of engineering in the UK, One Undershaft uses some similar construction elements and techniques in its structural system. Both the Leadenhall Building and 30 St Mary Axe show resemblances to the building’s structural components. In order to provide open office spaces with few obstructions from columns, the structural system of the building is an exterior framed tube of steel columns accompanied by central cores in reinforced concrete. The northern core contains elevator groups that transport people between the base, sky lobbies and top of the building, while the southern core contains elevators that operate between sky lobbies and office floors. Both cores also contain the main vertical ventilation channels and lavatories, which are placed in between elevator shafts, making excellent use of the cramped space on floors where these elevators aren’t accessible. For the exterior framed tube, the elegant architecture of Minoru Yamasaki was an important inspiration, which provided an alternative for the pure-glass façades that are built in the City. Because of the building’s narrow profile, the floors can be unobstructed from the centre to the facade, making flexible organisation of offices possible as a large part of the weight is directed toward the building’s perimeter. Additional large columns are provided at four spots in the building where there are no cores. Because of these limited distances, there is no need for extremely bulky floor constructions. The two cores are placed perpendicular to each other, so each core provides rigidity in one of the main axes. Both cores extend outward of the building, showing their position from the outside. This partially decentral position of the cores was a conscious decision as it freed up a large open space in the middle of the building. Contrary to buildings with a more square floor plate, the narrow building can still provide plenty of sunlight at this central position. The southern core sticks out of the buildings exactly next to the Leadenhall Building’s core. Given the limited distance between the two towers, this was considered as a place where the quality of offices at the façade would be limited. The northern core sticks out in the middle of the north façade. With the Highline Elevators at the exterior, passengers can look outside as they head all the way up to the top floors, while at night, the ascending and descending elevators can be observed from outside in the dark. At the west and east sides of the cores, an area 9 meter wide and 72 meter long provides well-lit office space. For the construction of the office floors, the building uses a similar system as the one in the neighbouring Leadenhall Building by Rogers Stirk Harbour & Partners. In order to increase the free floor-to-ceiling height, the steel beams are perforated at strategical positions to allow services to be positioned at the level of the beams instead of below them. These steel beams with web openings are placed in two directions. Two central beams run parallel to the length of the building from the ends of the northern core all the way up to the southern façade, while smaller beams run perpendicular to this, each one extending to one of the perimeter columns with a spacing of 1800mm, or 3600mm at the second half of the building’s height. On top of the steel beams is a steel metal deck covered with a concrete compression slab. Above it lies the raised computer floor. A dropped ceiling is placed below the steel beams.



Office floor construction. The position of the web openings with services running through them is a result of the ventilation layout. This will be explained later.

To provide additional rigidity against wind loads, outrigger trusses are located at the north and south side of the building, parallel to its shortest dimension, to counteract wind loads. Wind patterns in the eastern office cluster can get very complex and unpredictable as the building’s environment is constantly changing when new towers are being constructed. With its position in the centre of the office cluster, there is no clear main wind direction to be considered. Downdraught winds, typically caused by highrise buildings, can be reduced at the covered arcade because of its setback position. A thorough study through the use of wind tunnel tests is required to properly assess this problem. Perpendicular to the outrigger trusses, on the east and west side of the building and divided over base, middle and top of the building, are diagonal bracings or belt trusses which greatly increase the rigidity of the building. One of the earliest examples of the core-andoutrigger system is the former First Wisconsin Center by SOM Architects,. This building was used as an inspiration for this system. Similar to the diagonal bracing at the collective levels of the east and west façade, the bracing at the south façade reflects the collective character of the winter gardens behind them. Not only does this create a more tectonic feeling in the sky lobbies, the diagonal bracing also provides the required resistance against wind loads.

left: RSHP Architect’s Leadenhall Building with its hybrid system of external bracing, central megacolumns and excentric core. middle: SOM’s Wisconsin Center with its early use of the core-and-outrigger system. right: Yamasaki’s Ruitang Plaza Tower with its strong vertical expression and bent columns at the base of the building.

For the foundations, bored piles around the building perimeter, right underneath the external columns, are needed to provide enough strength in the relatively weak London clay. A thick concrete slab connects the foundations of the perimeter with those of the central cores. While the exterior columns measure 400 mm by 800 mm, the total thickness of the façade adds up to one meter because of the curtain wall and air space in between the inner and outer glass layer. The steel columns consist of two I-shaped profiles welded together, after which they are packed in a protective layer to provide suitable fire safety. The opaque parts of the façade are covered with fibre-reinforced concrete, which determines the colour of the façade.

Opposite page: east façade. The Leadenhall Building is visible behind One Undershaft, as well as 22 Bishopsgate on the right side, and Lloyd’s Building on the left side. The tiny church of St Helen’s Bishopsgate is visible on the right side. Scale 1:750.



EXTERNAL EXPRESSION The building’s multi-layered façade is the result of both aesthetic, performance-driven and functional design decisions. Firstly, a singleglazed transparent curtain wall envelops the building. A second, doubleglazed curtain wall on the inside of the façade provides the thermal break, and in between the two walls is the external frame of steel columns. This setup is used to create an energy-efficient double skin façade. Natural ventilation is included in the building to reduce the otherwise massive energy consumption of the building. Cold air can access the air cavity in between the inner and outer layer and increases in temperature, thus flowing upward. It can flow up for three floors, after which it has reached a higher temperature and can be used for ventilation of the offices. Visual considerations also had their impact on the façade. The outer layer runs uninterruptedly vertically for three floors, thus showing the three-storey organisational units of the offices. This layer is kept as transparent as possible in order to maintain depth in the façade. Behind it is the structural system of steel columns covered in a protective layer to provide fire resistance, which are connected with the composite floor slabs of steel beams with sliding bearings to allow small movements and reduce stresses in the columns due to thermal loads and wind loads. These beams are located right behind the opaque parts of the outer layer. These vertical opaque outer layer lines provide insulation while at the same time projecting the shape of the structure behind them. The inner curtain wall is perfectly straight, thus providing the most flexible use of space, as there are nog columns in the way. Over the different floors, a small horizontal shift of these windows breaks the rhythm and distinguishes the different offices. The organizational independence of the two stacked ‘buildings’ is highlighted by the change of the vertical column rhythm: the upper building has only half the amount of external columns of the lower part. Not only does this distinguish the two parts, it is also a logical result of the structural requirements of the upper half of the building, which has a much lower vertical load. As views from inside become more spectacular as we go higher up, the wider spacing of the colums opens up a wider view of the surroundings. One more visual consideration led to this wider spacing: as the upper part of the building is only seen from further away, the closely spaced columns would be harder to distinguish form afar. By changing the rhythm, the wider column spacing is better suited for being seen from large distances. The south elevation on the following page shows the narrow profile of the building. It shows the massive scale difference between the neighbouring St Andrew Undershaft and the modern office skyscrapers located in the medieval city. On the left of One Undershaft lies the Leadenhall Building, with its megaframed structure, which groups every seven floors into one visual entity. The highest tower on the left side is the Bishopsgate 22 project, which is under construction at the moment. At the right side of One Undershaft, we see the Heron Tower with its antenna and the famous St Mary Axe Building with its curved profile. The diagonal bracing visible on the façade is placed on the outer left and right side of the facade, both on the south and north, in order to provide plenty of resistance to wind loads. The bracing at the office floor levels reaches up for three floors, whereas the bracings at other functions vary in height. Again, all office floors are visually grouped in clusters of three floors to highlight their organizational unity. In the right weather conditions, the vegetation of the winter garden can be seen through the façade.

Opposite page: south façade. The narrow profile is set against the much wider Leadenhall Building. On the right side, 30 St Mary Axe is visible, as well as the Heron Tower in the background. The small church on the right side is St Andrew Undershaft. Scale 1:750.




raised computer floor (340mm) upper concrete compression slab (130mm) steel metal deck (60mm) secondary composite beam with web openings for integrated building services suspended ceiling with suspension mechanism (600mm)

single-glazed exterior window air cavity with daylight controlling, reflecting louvers double-glazed argon-filled, low-e interior window

grille for maintenance walkway upper ventilation louver lower ventilation louver louver frame

Above: Principal scheme of faรงade at office floors at equal scale with opposite page, showing the principle of the double skin faรงade with shading devices and air flow mechanisms in the air cavity. The scheme also shows the structure of the office floors (1:50). Opposite page: View on the faรงade at office floors, showing the grouping of three 73 floors into one cluster.

VENTILATION As up to 40% of the energy consumption in a high-rise office building goes to HVAC services, it is of utmost importance to make sure the building has an energy-efficient ventilation system. The well-being and productivity of employees is also greatly influenced by air quality. Natural ventilation, which has been used for thousands of years all over the world, has been introduced again in state-of-the-art systems in recent office buildings. Unfortunately, natural ventilation disappeared from office architecture in the second half of the twentieth century as cheap energy was made available to create an artificial climate in glass boxes. The natural ventilation could strongly reduce carbon dioxide emissions and contribute to a more sustainable building. A VNV system (Vraaggestuurde Natuurlijke Ventilatie or demand-driven natural ventilation) is implemented, which consists of three components (DUCO, 2015). The first component is basic ventilation via fresh air that is brought in the building through the double skin façade. A second part is the ventilative cooling, providing cooling using large flow rates and ducts. Finally, controllable solar blinds in between the two skin layers can reflect sunlight back outside or reflect it towards the office ceiling thanks to its airplane-wing-shaped profile. The natural ventilation can only be used when outside conditions allow it, so a hybrid system is required to make sure clean air is provided at all times, irrespective of weather conditions. This “Mixed-mode system” uses a mechanical system to complement the natural ventilation. The ventilation louvers in the double skin façade can be rotated to adjust to different situations: in winter conditions, air can flow in the double skin façade at the bottom of an office unit, after which it flows up because it is heated by heat losses from the inside glass layer. When this air flow enters the building, it will be preheated. In summer, the upgoing air will be pushed outside again instead of entering the building.

left: summer situation. excess solar radiation is reflected on the solar shading. Cold air enters the air cavity, rising as its temperature rises. The heated air leaves the air cavity three floors higher. As cold air enters the cavity, part of it can be used for natural ventilation. Mechanical ventilation can assist this via the supply vents in the ceiling. right: winter situation. sun rays are reflected upward inside the building. Cold air enters the air cavity, rises and - given the right climatic conditions - enters the building preheated. Mechanical ventilation can provide additional heating via the supply vents, this time via the floor.


Left image: three mechanical floors are spread out over the building. The lower mechanical floor provides services for the public program at the bottom levels, while two higher mechanical floors provide HVAC services for the two office blocks. These floors are lcoated on top of the floors which they operate, as it requires less energy to suck the air up rather than push it upward. The arrows on the left show the natural ventilation of air entering the building via the winter garden, which is located at the south side, which is the main wind direction of London. Blue lines are supply vents and streams, red ones are return vents and streams.

Right image: this diagram shows the air flow on a typical office floor. Two large shafts are located at opposite sides of the two cores of the building. The chosen layout provides a very simple yet efficient scheme that doesnâ&#x20AC;&#x2122;t require complex bends (thus causing energy losses) and provides short paths for incoming and outgoing air of no more than 9 meters. The arrows at the outside of the building show the possible natural ventilation which flows in the same direction of the blue incoming air, making sure the two air flows cooperate. The ducts in the center of the building are only required on floors where closed volumes (such as conference rooms) are lcoated at the center.


IV. A FURTHER LOOK INSIDE An overview of public, collective and office floors




VISITOR LOBBY & BARS Ground floor Following the wish to make the building more accessible to the public, the ground level is largely used for bars and coffee shops. The eastern promenade will have a large flow of people during peak hours, so two coffee bars are placed along the path to offer a quick beverage in the early morning. The larger central bar can be used throughout the day and will enable the site to remain activated in the evening after business hours. In the north, a separate lobby gives access to four elevators which only serve a small number of floors. These elevators lead all the way up to the top floors, where an exhibition hall, event space and top floor cafe are located. The external position of this elevator shaft offers stunning views during the quick ascent and brings a fascinating play of light in the skyline at night, when seen from the north. The west side of the building is used as serving space where small trucks can access a loading bay with a vehicle elevator which leads suppliers two levels down, beneath the bicycle parking, where loading and unloading happens. The western placement of these serving spaces follow the logic of the other neghbouring (planned) office towers.

The location of the public floors is reflected in the faรงade by the transparent and open faรงade. The diagonal bracing gives the faรงade a denser look as we go higher up. In between the vertical and diagonal columns lies the lecture hall level, which is the border between public amenities and collective office amenities.



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1 Visitor lobby to top floors 2 Bar 3 Goods elevator 4 Bicycle/Motorcycle elevator 5 Escalators to office lobby 6 Bar/Cafe 7 Arcade



OFFICE LOBBY & RESTAURANT First floor Entering the building via the wide escalator and stairs, the visitor has a number of options. On the north side lies the office lobby with the elevator shafts, where employees can use their personal pass at the elevator turnstyles, where the traffic management system will tell them which elevator will bring them to their destination as quickly as possible. Directly on the south side lies the large staircase which leads the visitor up towards the event space and lecture hall. As a third option, people can make a left turn right in front of this staircase and enter the buildingâ&#x20AC;&#x2122;s restaurant. Its close proximity to the office lobby makes it a perfect place for a business lunch during working hours, while it can be used in the evening during or after events, or simply be opened for the public. Visitors who have a meeting with someone in the building, are welcomed at the reception desk right in front of the entrance. While they wait for their host, they can wait at the lounge on the west side of the elevator shafts.



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1 Office lobby 2 Reception 3 Stairs to exhibition floor 4 Restaurant 5 Kitchen 6 Dining hall



EVENT SPACE & LECTURE HALL Second floor As we go further up, the public character of the building gradually changes into a collective office environment. In the transition zone of these two environments, between the public restaurant and the first sky lobby, lies the lecture hall. It is connected to a large event space spread out over the floor, making it suitable for both public events in the evening as conferences or lectures during office hours. The lecture hall can be closed off with tall curtains that can be moved across rails, as shown on the plan. The auditorium is placed on top of the wide main entrance in such a way that its slope goes in the opposite direction of the slope of the escalators and entrance stairs. Where the two approaching slopes would meet, the entrance of the building is located. Next to the lecture hall are serving spaces as well as a cloakroom and a bar for drinks during events or after lectures. A large staircase in the middle of the event space leads directly to the first floor lobby, connecting it to the restaurant and the exterior. Another staircase at the southern side of the floor leads people to the sky lobby, again creating an easy access along different functions.



second floor

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1 Event space 2 Foyer 3 Lecture hall 4 Movable curtains 5 Cloakroom 6 Bar 7 Reception area 8 Serving space 9 Lounge 10 Event space



SKY LOBBY +4 The two sky lobbies, located below each of the two office blocks, function as the interchange between the public city and the private office. These floors are places where every office worker of the building passes as he makes his way from the express elevators to the office elevators. While a straight path leads the way between the two elevator groups, a deviation from this route gives the opportunity to grab some breakfast before work, get a quick coffee or have lunch from one of the food stalls. Opportunities for informal meetings or business lunches arise from the set-up of chairs, lounge seats and tables that are spread over the open floor. An early coffee before work can be enjoyed in the morning at the eastern chairs when the sun shines on that side of the building, while the west side lounge might be preferable in the afternoon. These sky lobby floors are each accompanied by an amenities floor right above it. Where the lower amenities floor is conceived as a secondary street in the air with a copy & graphics services shop, a hairdressers, dry cleaning service, magazine and convenience store, as well as a small day care for the youngest children of employees, the upper amenities floor features a sports area with spectacular views over the City. A physiologist, general practitioner and dentist office at that same floor provide easily accessible healthcare. All of these amenities make sure that the office building is more than a place for work, and that employees have a multitude of services right at hand as to save time in their busy lives. Finally, the south sides of each of the sky lobbies give way to a large, sunlit atrium where employees wait for their office elevator to arrive.




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1 Elevators from lobby 2 Lounge 3 Highway to office lobby 4 Bar 5 Informal meeting area 6 Restaurant 7 Buffet counter 8 Kitchen 9 Office lobby 85


Lower amenities +5 With over 6000 office workers, One Undershaft forms a city on its own. By providing a wide range of amenities, the building offers a place where people can do more than just work. During a short lunch at noon, employees can go to one of two amenity levels, each one connected directly to the sky lobby. This first amenities level offers a daycare for young children of employees, a small grocery store, a copy service, a hairdresser and a drycleaning service. In the morning, parents donâ&#x20AC;&#x2122;t have to worry about getting their children to a daycare if they work at One Undershaft: they can simply take their children with them on their way to work and take them home afterwards. The other services on this level are chosen because they can save precious time during the busy workdays of employees. Just like on most other floors, toilets are fitted in between elevator shafts at places where the elevators are not accessible, in order to make good use of the otherwise wasted space.


Lower amenities +5

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1 Daycare 2 Dorm 3 Indoor street 4 Grocery store 5 Service corridor 6 Storage room 7 Copy & graphics service 8 Hairdresser 9 Drycleaner 10 Lunch area services 11 Goods deliveries


CONFERENCE ROOMS Floor 31 While the lower sky lobby is located right next to a large lecture hall and event space, the upper sky lobby lies adjacent to a floor with several conference rooms. These conference rooms of different sizes are placed along a wide eastern corridor which can be used as a reception area and foyer. Each conference room lies adjacent to serving spaces where chairs, tables or food can be stored. The two central conference rooms are separated by a mobile wall of panels which can be moved and removed, as to change the size of the two spaces as desired or to turn them into one large space. These conference rooms can be used for lectures, special events or gatherings of employees that could not be held at the office floors themselves. At the southern end of the floor is another reception area with a wide view on the Thames and Southbank.

A wide indoor boulevard runs parallel to the conference rooms. With no events taking place, the long space can be used as a lounge, but during or after the events, the corridor can be used for receptions, as it is directly connected to the bar at the south side of the floor.



Floor 31

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1 Conference room 133 seats 2 Storeroom 3 Lecture hall 180 seats 4 Foyer 5 Exhibition space 6 Reception area 7 Bar


UPPER SKY LOBBY Floor 32 Similar to the lower sky lobby, the upper sky lobby functions as an interchange, a metro station to step from one elevator into another, and to reach amenities quickly. The upper sky lobby is located in between the conference rooms level and the upper amenities level. The entire east side of the floor is a vide, which spatially connects the different floors. As the upper amenities level follows the same logic, the stack of the three floors forms a narrow but monumental space with a height of 16 meter. At the level of these three floors, the closely spaced vertical columns of the lower half of the building change their rhythm through the diagonal bracing that envelopes the confere rooms, sky lobby and amenities. The image below was taken in a model at the sky lobby level and shows how the spacing incresases further up, eventually going from a 1,8 m spacing to a 3,6 m spacing.



Floor 32

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1 Elevators from lobby 2 Lounge 3 Highway to office lobby 4 Bar 5 Restaurant 6 Buffet counter 7 Kitchen 8 Office lobby 91


UPPER AMENITIES Floor 33 In a city where seventy-hour work weeks are no exception, the office building should provide more than a desk and coffee machine. Getting from the 52th floor to the streets requires precious time in the busy lives of office workers, so it is beneficial to provide as many services in the building itself. The second amenities floor, located on top of the upper sky lobby, includes a fitness space, group sports area, sauna, as well as a medical corner with a physiologist, dentist and general practitioner. With the phrase ‘A healthy mind in a healthy body’ in mind, the fitness area can be used during breaks, before or after working hours to allow employees to get up from their chairs and have an informal chat with other employees from different companies. A central block provides showers, locker rooms and sauna spaces. For those following physiological therapy, there is a convenient connection between the physiologist’s office and the fitness area.



Floor 33

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1 Reception doctors 2 Physiotherapist 3 Physician 4 Backroom doctors 5 Dentist 6 Fitness area 7 Fitness reception 8 Group sports hall 9 Storage fitness 10 Locker rooms 11 Sauna


OFFICES Winter garden as a place for shared office space and interaction

All office floors are clustered in units of three floors. The main reason for this clustering is to make more efficient use of common workspaces which are not used all the time in regular office buildings. By sharing these meeting rooms with different companies spread out over three floors, they can be used more often while not requiring too much space for each company. Furthermore, the clustering provides a space for interaction between office workers of different companies. This opportunity is provided by the implementation of a winter garden area at the elevator lobby. When office workers or clients step out of the elevator, they immediately step into the lush winter garden with a magnificient view towards the south, to the Thames. The winter garden provides a less formal atmosphere where a lounge and the reception area are located, and connects the three floors via stairs and vides. Both employees and visitors arrive at the office floor in the central elevator lobby at the south, which is closed off for fire safety purposes. One can either head directly to the offices in the north, or go through the doors in the south towards the winter garden. The southern area is accessible to all office workers of the three connected floors, whereas only employees of that certain floor can access the offices themselves. The central position of the entrance towards the winter garden and elevator lobby enables the division of an office floor in even smaller units, so two companies can use the same floor. Thanks to the exterior framed tube construction, an open, flexible space makes up the majority of the office space, thus allowing for a large variety of office lay-outs. On the following pages, three floors which can be combined as one unit with a shared winter garden are shown. Each plan follows a different office layout principle. The first one has an open office landscape, where the second one is divided in separate cubicles and offices. A third alternative shows a mixture of these two options. Another great advantage of this organization with its shared winter garden, is that larger companies can occupy multiple floors with a central location at the winter garden, where each floor can be organized in a completely different way. One floor can have an open office plan, while another one has closed offices. The winter garden, with its southern position, provides an intermediate climate between outside and inside, which can be integrated in the system of natural ventilation. In between the outer and the inner layer of the facade, the wintergarden gives way for greenery, as an ideal space for office workers to take a break without going for a long ride to the ground floor. This space enables informal interaction between people of different companies which are situated in the same unit of three floors. The central position of the wintergarden makes it a passage towards the elevator lobby, the shared meeting rooms and the office entrances. This way, most of the flow of employees will pass here. Around the winter garden, seen on the left side of each plan, different common meeting places are situated. Each floor has different types of rooms, ranging from very small cubicles to larger meeting rooms. The different types are as follows: refuge room (1 or 2 people), enclave room (3 to 4 people), team meeting room (5 to 8 people), assembly room (10 or more people) and community spaces, which are mostly directly connected to the open office plan with no physical barriers (Knoll, 2012). The small refuge rooms can be used when a task requires more concentration, for long phone calls or video chat meetings or when two people want to discuss matters privately. The enclave and team meeting room are more suitable for small group meetings and are equipped with beamers and television screens for video calls or presentations. The even larger assembly rooms at the top floor can be used for bigger meetings. Opposite page: Winter garden as seen from the lower floor. An informal area with a kitchen, tables and sofas provides a common space for lunch breaks. The 1,80 meter wide space along the perimeter around the box-shaped rooms provides plenty of space for chairs and small tables where informal meetings can take place or independent work can be carried out. Lush vegetation is placed on the three floors of the winter garden, where larger plants or trees species with small roots, that is - can reach up to three ceilings in the center of the lower floor. 94


OFFICES Floors 6-29

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1 Office elevators 2 Reception area 3 Winter garden 4 Storage 5 Technical space 6 Service elevator 7 Goods elevator 8 Open office space 9 Copy room 10 Cloakroom 11 Toilets 12 Kitchen 13 Small meeting room 14 Team meeting room 15 Conference room 16 Breakout area 17 Focus space


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1 Reception area/elevator lounge 2 Wintergarden 3 Refuge space 14 4 Enclave room 5 Team meeting room 6 Assembly room 7 Community space 8 Kitchen 3 9 Open offices pantry? kitchen breakout area vestiaire (?) copy...


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BICYCLE & MOTORCYCLE PARKING Floor -1 When trying to compete with Londonâ&#x20AC;&#x2122;s excellent underground network, convenient bicycle facilities can stimulate people to come to work by bike. To make life easy and considering the scarce amount of available space in the City, a large elevator is placed at the back of the building to transport bicycles and motorcycles to the parking at minus one. A comfortable bicycle slope would have consumed about 80 meters of valuable public space, and even a steep slope combined with stairs would require about 30 meters. Therfore, the somewhat more expensive elevator seemed a good alternative. After employees arrive by bicycle or motorcycle, they have access to a locker room to leave their cycling gear or helmets in the locker room for the day. They can then continue to a locker room with showers, more lockers and toilets to freshen up before they start their day. After that, they can easily continue to the elevator shaft that can bring them straight up to the lobby. Below this floor is another parking level that can be used sporadically for cars, as most people arrive by public transport, on foot or by bicycle or motorcycle. This floor also contains a (un)docking bay for vehicles delivering goods to the building. The footprint of this lower floor is larger and extends further to the east, so vehicles can exit the vehicle elevator, driving through the northern core.



Floor -1

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1 Men’s locker room 2 Women’s locker room 3 Delivery/car elevator to -2 4 Locker space 5 Bicycle/Motorcycle elevator 6 Technical space 7 Elevators to lobby 8 Motorcycle parking 9 Bicycle parking 10 Goods elevator 11 Service elevator


The long, open space at the penultimate floor stretches out over the entire length of the building. The seventy meter long space with its panoramic view can be used for exhibitions or events and is accessible to the public under normal circumstances.



Looking back at the design process of the last months, it is quite surprising to see the massive amount of new information in such a wide range of building aspects that I gathered. The organization of modern offices, structural systems of high-rise buildings and double skin façades are only a few out of a long list of topics that I studied. Still, the design decisions and solutions applied in my design might not all be revolutionary nor perfect. However, the first part of this thesis has taught me that even some of the most prized marvels of high-rise architecture and engineering contain flaws. While the high-rise typology inevitably brings about some complex problems, it offers many unique solutions to the difficulties of modern urban situations where space has become more and more valuable. Each day, new proposals for spectacular skyscrapers appear, often as status symbols to exhibit wealth in the most exclusive and expensive way. Although skyscrapers are often associated with this type of world, it is certain that high-rise architecture will serve many other crucial causes, whether it is for offices, housing or new functions such as vertical farming. Probably the clearest lesson I learned in the last semester, is that with every ingenious design decision, a new problem arises, causing the architectural process to be a work which could go on forever. The buildings in the City that are considered as the most succesful in terms of international notoriety, such as the Leadenhall Building and 30 St Mary Axe, are buildings that were thought through countless times, often throwing away entire elaborated design proposals, while a large team of architect and engineers spent multiple years designing the final project. Given the limited amount of time, I tried to apply as many aspects of high-rise design in One Undershaft using the experiences of other designers. Looking back at A story of storeys and its sometimes critical view on highrise architecture, I now notice - after having faced the many problems peculiar to designing a high-rise building - that some conflicting interests canâ&#x20AC;&#x2122;t be fully harmonized. In terms of all three themes that I worked on, I experienced some crucial contradictions. More office space in the air naturally brings about obstructed views, more qualitative public facilities oppose financial interests for developers, and a generous supply of office amenities, again, might endanger developerâ&#x20AC;&#x2122;s incomes. In the end, finding the right balance between extremes often leads to overall good architecture.



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Profile for Michael Van Steijvoort

A Game of Towers: The Rise of High-Rise Architecture in the City of London  

A Game of Towers tells the fascinating story of the City of London's changing skyline. Dotted by dozens of church spires throughout most of...

A Game of Towers: The Rise of High-Rise Architecture in the City of London  

A Game of Towers tells the fascinating story of the City of London's changing skyline. Dotted by dozens of church spires throughout most of...

Profile for michaelvs