London City Hall

LONDON CITY HALL

Luigi Di Vito Francesco

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LONDON CITY HALL Summary I.

II.

III.

IV.

V.

VI.

VII.

VIII.

INTRODUCTION 1. The building 2. Location 3. Competition and design 4. Symbolism and influence 5. Pictures

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AIR 1. Ventilation 2. A giant radiator 3. Drawing

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LIGHT 1. Pictures 2. Drawing of lights 3. Light 4. Shadows

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EARTH 1. Structure 2. Materials 3. Diagrid system 4. Glass

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WATER 1. Use of water 2. Drainage system

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ENERGY 1. Energy savings 2. Solar panels and movement sensors

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RECYCLE 1. Recycling

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CONCLUSION

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Luigi Di Vito Francesco

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LONDON CITY HALL

I. INTRODUCTION The building City Hall is the headquarters of the Mayor of London and the Great London Assembly (GLA).

GLA (Greater London Authority) logo

A photo of the architect

The building was designed by the British architect Norman Foster.

The building is 45 meters high, with 185,000 sq ft (gross) of floor space spread over 10 floors. In conventional terms, the building has no front or back: its shape is derived from a geometrically modified sphere.

This hybrid form is designed to minimize the surface area exposed to direct sunlight.

The building has been designed to be as green as possible.

London City Hall is part of a development project on the South Bank of river Thames called More London; the project was developed by the architecture firm Foster and Partners.

It includes the City Hall, 4 places, 4 buildings, a kiosk and a fire station. Many restaurants, cafes and shops are held in the 4 buildings.

Map of More London project

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LONDON CITY HALL

I. INTRODUCTION Location The building is located on the south bank of the river Thames in the London Borough of Southwark, 10 minutes walking from London Bridge Underground and National Rail Station.

Map which shows City Hall’s links with the city

The building‘s location

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LONDON CITY HALL

I. INTRODUCTION Competition and design The headquarters for the Mayor of London was commissioned well in advance of the elections held in 2000 that restored to London a measure of strategic local government. In 1998 competing proposals were put forward to house the GLA in Royal Victoria House, Bloomsbury, where a conversion by Will Alsop was on offer, and in a custom-made building developed as part of London Bridge phase II. The latter option was selected by the government. After a classical revival scheme designed by John Simpson was abandoned, a new masterplan for the second phase of London Bridge City was commissioned from Foster and Partners.

John Simpson's proposal

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LONDON CITY HALL

I. INTRODUCTION The design for London City Hall was part of a developer-led competition, which asked for submissions according to a design brief that required the promotion of transparency and democracy. In addition to these requirements, Foster and Partners incorporated their own environmental goals for the project. In order to produce an energy-conscious design, architects began to collaborate with engineers, Arup, early on in the design process.

Together, Foster and Partners and Arup worked to design the initial London City Hall submission, which took the form of a conventional office block with a debate chamber positioned at the end.

After selecting Foster and Partners to take on the project, the jury, consisting of political and professional representatives, described the desire for a more iconic building form.

With this direction in mind, the design team took the sketch that appealed to the jurors and began to reassess the presence of the brief requirements. At this point, volumetric studies were done by manipulating and altering the weight of the brief. As the design sequence progressed, the building began to take the form of a more dynamic shape that was conceptually driven by the detailed brief requirements. Advanced computer modelling Techniques helped to create iterative studies of 3D models throughout the design process.

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LONDON CITY HALL

I. INTRODUCTION Symbolism and influence According to the architects, the building "expresses the transparency and accessibility of the democratic process and demonstrates the potential for a sustainable, virtually non-polluting public building".

The transparent glass exterior allows the citizens of London to feel like they are a greater part of their governing body.

The transparent façade allows Londoners to see directly into the operating chamber, symbolizing an open system of government.

City Hall design and symbolism was strongly influenced by one of Foster’s previous projects, the Reichstag Dome in Berlin. As for the City Hall, the Reichstag is symbol of transparency of the democracy and environmental sustainability.

The Reichstag Dome in Berlin

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LONDON CITY HALL

I. INTRODUCTION Pictures

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LONDON CITY HALL

II. AIR Ventilation The building is naturally ventilated, with openable windows in all office spaces.

In summer the City Hall is kept cool through the use of groundwater. During winter part of the air coming from the outside is used to heat the building.

How air flows in offices

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LONDON CITY HALL

II. AIR A giant radiator Very important is also the function of the diagrid structure which doesn’t work only as structure but also as a radiator, as Arup stated: “The diagrid structure supports the north façade of the GLA building and is in fact the largest radiator in London. The majority of the horizontal steel elements, measuring a staggering 300mm in diameter each, have hot water coursing through them to act as a discreet heater for the atrium space that doesn’t require extra fittings or pipe work installation.” (Arup 2002)

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LONDON CITY HALL

II. AIR Drawing that shows how the air flows around the building (random colours have been used to show different directions of the air)

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LONDON CITY HALL

III. LIGHT Light The architect decided to give the building its particular shape to reduce energy consumption. Thanks to its shape and orientation (the building is oriented towards the south) natural and artificial light are perfectly mixed in all the environments of the building.

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LONDON CITY HALL

III. LIGHT A corridor at the ground floor which is non-subjected to natural light

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LONDON CITY HALL

III. LIGHT The drawing show light at underground floor

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LONDON CITY HALL

III. LIGHT Shadows Two sketches that show how the shadows of the City Hall change during the year

Winter solstice: 21st December

Summer solstice: 21st June

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LONDON CITY HALL

IV. EARTH Structure The building is 45 meters high, with 185,000 sq ft (gross) of floor space spread over 10 floors. In conventional terms, the building has no front or back: its shape is derived from a geometrically modified sphere. This hybrid form is designed to minimize the surface area exposed to direct sunlight. The building has been designed to be as green as possible.

The building structure consists of a central tower made of reinforced concrete around which was constructed the rest of the building.

The building under construction

The concrete core has an important structural function as it is the only vertical element that starts from the foundations and supports the loads of the upper floors.

The concrete core of the City Hall

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LONDON CITY HALL

IV. EARTH Materials Renewable materials have been used which include: glass, steel and concrete.

Even if the building symbolizes modernity no natural materials have been used.

Steelwork:

Structural frame - 2100 tons

Concrete (core):

13,100 sq. m Reinforced

1950 tons

Cladding: 7,300 sq. m of triple glazed low emissivity coated clear glass, incorporating shading devices.

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LONDON CITY HALL

IV. EARTH Steel - Diagrid System London City Hall is one of the few building constructed using the diagrid (diagonal grid) structure.

In the City Hall diagrid is used to support only the glass facade while in other recent building (Gherkin, Hearst Tower etc.) diagrid has been used to support the whole building. This makes the City Hall a unique building.

The diagrid structure has been used prevalently for today’s tall buildings worldwide, it requires less structural steel than a conventional steel frame.

Diagrid structures create triangular with diagonal support beams.

Diagrid node Diagrid advantages - increased stability due to triangulation - elimination of vertical columns - ability to provide structural support for hundreds of shapes - reduced use of structural materials which translates into environmental savings - reduced weights of the superstructure translates into reduced load on the foundations

Diagrid disadvantages - Constructability is a serious issue in diagrid structures because its nodes are more complicated than those of conventional orthogonal structures.

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LONDON CITY HALL

IV. EARTH Glass The building makes use of four different types of glass including double glazing and triple glazing used whit the specific aim to keep the building warmer, saving relevant quantity of energy.

The glass can be treated to make it more energy efficient, and the air gap between the glass panels can be filled with an inert gas such as argon, krypton or xenon, to help to reduce the heat loss.

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LONDON CITY HALL

V. WATER Water Water has a fundamental role in the building’s HVAC system.

The building makes use of ground water which is pumped up into the building through boreholes at a temperature of 12-14 °C. This water is used to cool the building; in fact many horizontal steel elements are filled with it to maintain a comfortable internal temperature.

After being used in cooling and having reached a higher temperature the ground water is used to flush toilets.

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LONDON CITY HALL

V. WATER Drainage system A new drainage system was installed in to solve the problem of standing water around the perimeter of the building.

Pictures of the drainage system

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LONDON CITY HALL

VI. ENERGY Energy savings London City Hall symbolizes modern architecture.

Due to its egg shape, which has made possible a sensible reduction of the building’s surface (about 25% less than the equivalent rectangular building), noticeable results have been achieved in terms of energy savings.

The energy consumption has been greatly reduced by using ground water instead of refrigeration to cool the building.

The installation of a new voltage system by Powerstar allowed a sensible reduction of the energy consumption of 13.6% as shown in the graph below.

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LONDON CITY HALL

VI. ENERGY Solar panels and light sensors

In 2007 solar panels were installed on the roof of the building to further reduce cooling and heating costs.

Photovoltaic cells work by converting sunlight into electricity. Photovoltaic technology is safe, proven and does not release any emissions that contribute to climate change.

The solar panels send power to the electrical system and HVAC systems reducing the building’s CO2 emissions.

The building has numerous light sensors (Simmtronic SPK28, shown in the picture below) and switches that are software programmable to provide a versatile and intelligent lighting control system.

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LONDON CITY HALL

VII. RECYCLE Recycle

Many of the building’s elements are made from recycled materials, in order to reduce environmental impacts, improve performance, and optimize occupant health and comfort.

Heat produced by computers is recycled.

After being used for cooling the building, water is used in toilets.

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LONDON CITY HALL

IX. CONCLUSION Even if the building had many problems (the break of one of the boreholes and the substitution of its drainage system) during its first 10 years of life, and it is not totally sustainable as initially expected, these elements are not enough to sentence the failure of the project.

Great results have been achieved thanks to the architect’s attention to environmental questions.

Luigi Di Vito Francesco

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