FROM ECO-EFFICIENCY TO ECO-EFFECTIVENESS - Case study 2

London City Hall Foster and Partners Urbanism Construction Date: 1998 to 2003 Regional context: London - Urban riverside area Climate: temperate

Social Function: Corporate Biosphere A sustainable building – a delicately balanced and interconnected set of human, architectural, and environmental subsystems.

The building offers flexible office space that can be sub-divided Building typology: into as many cellular offices as Government offices. required or kept open-plan.

City Hall is home to the Mayor of Partitions can be solid or London, the London Assembly and transparent. The Chamber allows the Greater London Authority a number of different uses, Also accommodates; gallery, configurations and functions. public library, committee rooms, Collective Spaces administrative offices, and restaurants. There is a visitor center More than half of the total site and a flexible exhibition and area is given over to public space, function space at the higher levels including two large piazzas. with a public viewing gallery at the top.

"Members of the public may visit parts of City Hall” Building Cost: The 201,650-square-foot building was constructed for £43 million (about $64 million).

Exhibition space on the 2nd floor, with a view of the Assembly Chamber where many public meetings are held Many public meetings are held in the Chamber at City Hall, which is on the 2nd floor and has seating for 250 members of the public.

McGrow Hill Construction, Architectural Record 02/2003

Urbanism

DIA - Architectural Theory WS08/09 Prof. Gunnar Hartmann

Banush Shyqeriu

London City Hall Foster and Partners Urbanism

At the top is a space with a terrace overlooking the city, called “London's Living Room,” which can be used by the public for exhibitions and events.

‘Corporate Biosphere’ - Assembly Chamber

The Scoop

The Scoop is an outdoor area to the west of City Hall: a sunken oval amphitheatre made of grey limestone. It can seat 1000 people, and is a popular space on a sunny day. It can be accessed from the riverside walkway by a curving ramp and by steep steps McGrow Hill Construction, Architectural Record 02/2003

Urbanism

DIA - Architectural Theory WS08/09 Prof. Gunnar Hartmann

Banush Shyqeriu

London City Hall Foster and Partners Energy Generating Energy In order to reduce the building's electrical consumption further, in 2007 solar panels are being installed on the roof of the building, to allow City Hall to generate its own solar power.

Building Efficency Minimising the surface area of the building results in maximum efficiency in energy terms. The building's form is derived from a sphere, which has approximately 25 per cent less surface area than a cube of the same volume.

The energy strategy for City Hall enables it to run on a quarter of the energy consumed by a typical high specification office building.

Together, the features implemented in this project reduce the energy load of the building by 75 percent, compared The solar diagram for the City Hall building to similar-size office buildings The architect and its engineering elsewhere in London. partner, Arup, decided early on that the building would be designed as an energy-efficient entity.

Arup engineered every aspect of the facade to minimize heat transfer across the external surfaces. The maximum allowable solar heat gain for each external The state of the art photovoltaic solar square meter of building was panels on the roof of City Hall will reduce determined by constructing and the CO2 emissions of City Hall by 1,000 analyzing heating and coolingtonnes in 20 years – enough to fill 3,000 hot air balloons! load models.

McGrow Hill Construction, Architectural Record 02/2003

Energy

DIA - Architectural Theory WS08/09 Prof. Gunnar Hartmann

Banush Shyqeriu

London City Hall Foster and Partners Energy Structure played a major role in creating an efficient and integrated network of systems. A diagrid structure supports the north-facing facade. Hot water courses through horizontal members, 12 inches in diameter, warming the atrium and creating, in essence, London's largest radiator. Structure that doubles as plumbing illustrates the economy of systems integration.

Furthermore, the building leans back toward the south, where floor plates are stepped inward from top to bottom, providing natural shading from the most intense direct sunlight. On the north side, where there is no direct sunlight, the glazing is clear.

1. Main entrance 2. Exhibition space 3. Physical plant 8

4. Ramp 5. Assembly chamber 6. Offices 7. Elevator/core 8. London’s Living Room

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The solar diagram for the City Hall building

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Heating flow W elded-steel T-section

Steel tube

SECTION THROUGH ROOF

P H OTO G RA P H Y: Š N I G E L YO U N G / FO S T E R A N D PA RT N E R S ( O P P O S I T E )

Double glazing

The use of this natural resource for cooling reduces electricity consumption and thus saves money. Boreholes use less energy than do conventional chillers and cooling towers, and they are less expensive to install and maintain.

Following circulation, the ground (aquifer) water is used to flush toilets before being discharged, further reducing water consumption.

McGrow Hill Construction, Architectural Record 02/2003

Energy

DIA - Architectural Theory WS08/09 Prof. Gunnar Hartmann

Banush Shyqeriu

London City Hall Foster and Partners Construction Materials local / renewable materials Generally renewable materials have been used, which include; glass, steel and concrete.

The obviously high-tech building symbolizes a new progressive agenda, and energy savings are an important part of that, though that isn't immediately apparent: There are no natural materials, stony thermal masses, secondary outer shells, or other staple features of sustainable design.

Most of the skin on the GLA is actually opaque, but that isn't noticeable since the solid insulated silver aluminium panels that cover three fourths of its surface are sheathed by plates of shiny glass.

The penalization of the building skin was determined by analyzing sunlight patterns throughout the year.

Three-quarters of the facade is composed of opaque panels; the transparent areas have adjustable blinds.

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, incoporating shading devices

Embodied energy – The building construction was quite efficient considering: construction time – 30 months, construction method – combination of on-site works and prefabrication – CAD/CAM manufacturing of several parts of construction and cladding.

Not only for the building’s architecture and construction, but for the materials used as well, were attached equal importance to aesthetics, function and sustainability http://www.architectureweek.com/2003/0312/design_3-2.html greeneconomy.wordpress.com/ http://www.emporis.com/en/wm/bu/?id=159693

Construction

DIA - Architectural Theory WS08/09 Prof. Gunnar Hartmann

McGrow Hill Construction, Architectural Record 02/2003

Banush Shyqeriu

London City Hall Foster and Partners Construction Construction Method

Thermal-insulation vapor barrier Perforated-sheet-metal sunscreen

- Each City Hall's glass panels is unique and is cut by laser, - City Hall is clad with 3,844 glass panels (7,300 square meters) of triple-glazed, low E glass incorporating shading devices.

Arup Facade Engineering assisted the architect from concept stage to develop cladding strategies that would meet the demanding environmental requirements within a tight cost plan.

Two generic cladding types were used, comprising a unitised thermal flue curtain wall construction for the offices, and a toggle-fixed steel and glass design for the more public areas.

The office cladding consists of 1.5m wide modules.

Each panel is an individual storeyheight flue with an inlet and outlet for natural ventilation with manually operated opening vents at high and mid level.

The team developed the cladding design to a high level before tendering to reduce cost and programme risks.

Double glazing Steel tube beam

Aluminum sunshade

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02.03 Architectural Record 119

Construction lifespan Intended lifespan – The building has longlasting lifespan in terms of structure, materials and functional flexibility.

Programmatic reuse - The building offers flexible office space that can be sub-divided into as many cellular offices as required or kept open-plan. Partitions can be solid or transparent. The brief required provision for 54 cellular offices with the remaining space open-plan.

The Chamber allows a number of different uses, configurations and functions. http://www.arup.com/facadeengineering/project.cfm?pageid=1799 McGrow Hill Construction, Architectural Record 02/2003

Construction

DIA - Architectural Theory WS08/09 Prof. Gunnar Hartmann

http://www.architectureweek.com/

Banush Shyqeriu

London City Hall Foster and Partners Construction Material Reuse Many of the building elements, including floor tiles and rubber doormats, are made from recycled materials.

Sustainable design includes the informed selection of materials and products to reduce product cycle environmental impacts, improve performance, and optimize occupant health and comfort.

City Hall is one of the most energy efficient and sustainable structures in the capital due to natural solarshading realised via the inclination of the south face of the structure; the use of artesian well-water pumped from 65m below the surface to provide all building air conditioning; the subsequent use of artesian well-water for toilets and other non-potable uses within the building; energy efficient cladding panels; and the use of recycled building materials.

Different parts of the building required individual raised floor solutions according to how they are used. In areas that are in constant occupancy (e.g. offices), fresh air is supplied via low-leakage plenum floors, through displacement floor grilles set into a raised floor platform of medium grade RMG 600.

PSA rated steel encapsulated/particle board construction, loose laid raised access floor panels.

http://www.arup.com/facadeengineering/project.cfm?pageid=1799 McGrow Hill Construction, Architectural Record 02/2003

Construction

DIA - Architectural Theory WS08/09 Prof. Gunnar Hartmann

http://www.architectureweek.com/

Banush Shyqeriu

London City Hall Foster and Partners Light & Air

Air Technology Indoor air quality

Air Comsumption heating & cooling systems A sphere has 25 percent less surface area than a cube of the same volume. Less surface equals less heat and cooling gains.

The building is naturally ventilated, with openable windows in all office spaces. Heat generated by computers and lights is recycled.

High-level automatically controlled window

Air out

Air out

Electrical consumption is reduced by avoiding refrigeration and using cold ground water to aircondition the building.

Air for ventilation enters offices through grilles in the floor. Vents in the facade are provided in the external offices for natural ventilation.When the vents are opened, local cooling and heating systems will be deactivated.

During winter, heat and moisture will be recovered from the outgoing air and used to condition incoming ventilation air using devices called hygroscopic (the property of readily absorbing water) thermal wheels.

IWhen heating is required, two gas-fired boilers generate hot water for use in convector heaters in the offices, in the debating chamber, and for the underfloor heating of the foyer. The hot water runs through heating coils in the airhandling units, warming incoming air.

Air in Manually operated opening vent

Air in

McGrow Hill Construction, Architectural Record 02/2003

Light & Air

DIA - Architectural Theory WS08/09 Prof. Gunnar Hartmann

Banush Shyqeriu

London City Hall Foster and Partners Light & Air In the summer, comfortable internal temperatures are maintained by chilled beams, rather than electric chillers. The ground water is pumped to a height of 410 feet at a temperature of 53 to 57 degrees Fahrenheit from the aquifer below

the building via two specially drilled boreholes. This cold ground water is also used directly in the cooling coils of the air-handling units to cool the fresh air entering the building. The use of this natural resource for cooling reduces electricity consumption and thus saves money.

ENERGY CONSERVATION STRATEGIES

Minimum surface area faces the summer sun

Building form provides self-shading in summer Openable windows to perimeter of office areas

Maximum sunlight reaches the river walk

Fresh air

Chamber oriented due north to minimize solar impingement

• Spherical form minimizes surface area reducing heat loss and heat gain • Responsive cladding system: Shading relates to building orientation • Intergrated energ y-circulation system • Passive cooling with chilled beams

Exhaust air

Heat exchanger

Gray-water tank Borehole cooling

• Chamber can be naturally ventilated • Perimeter natural ventilation

McGrow Hill Construction, Architectural Record 02/2003

Light & Air

DIA - Architectural Theory WS08/09 Prof. Gunnar Hartmann

Banush Shyqeriu

London City Hall Foster and Partners Light & Air

Lighting Technology

The control system for City Hall comprised a high volume of customised Simmtronic architrave The Building is naturally lit, reducing the lighting consumption switches to integrate into door mullions and special multi-gang plates to operate the circulation areas.

Simmtronic's SPK.28 architrave switches can be individually configured to select or Opaque glass cycle between lighting scenes Fade with adjustable fade rates.

Clear glass Universal head sensors provide the presence detection sensibility, high resolution linear Clear glass light measurement and multicommand infra-red control.

All switches and sensors Clear glass are software programmable to provide a versatile, intelligent and fully addressable lighting control Fade system.

This simplified the modular lighting controls to a three-wire system for cost effective installation whilst providing the Opaque glass GLA with a very flexible building.

Lighting Comsumption

NATURAL VENTILATION DIAGRAMS

Energy consumptions for GLA's environmental systems is less than half levels in DETR good practice office guide.

60,000 sq ft

3,312 luminaires

McGrow Hill Construction, Architectural Record 02/2003

Light & Air

DIA - Architectural Theory WS08/09 Prof. Gunnar Hartmann

http://www.simmtronic.com/home.html

Banush Shyqeriu

London City Hall Foster and Partners Greenery, Water & Waste Multi-Performance building's performance within the ecosystem

The building has an extensive Multi-Performance, first the shape of the building performs as natural shader for the sunny side, by also reducing wind in pedestrian area.

NORTH

As environmental comfort is determined by air movement, ambient temperature, humidity, air intake and exhaust, and solar radiation. Building systems can be optimized only if the designers understand the interaction and interdependence of each system with every other system.

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1st Sep 1st Apr

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1st Nov 1st Feb

The multi-performance of this building relies in its urban context – creating a social outdoor space interconnected with accessible to public indoor spaces- its shape which is a efficient outcome of extensive analysis of external systems; daylight, air and energy flow, and the connections of this systems with internal systems; indoor comfort in terms of energy flow, air, temperature, humidity, also the social interactions promoted by the qualities of these systems.

Natural shade from direct sunlight is provided by the distinctive stepped façade and any

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1st Jan

solar position stereographic projection

City Hall of the Greater London Authority responds well to its local climactic environment. The 31 degree tilt of the south facing facade means the the floors will be shaded well by the floors above during the summer months, and they will admit more direct natural light during the winter months. The building also has computer controlled operable windows which allow for natural ventilation from the prevailing winds.

Greenery, Water & Waste McGrow Hill Construction, Architectural Record 02/2003

DIA - Architectural Theory WS08/09 Prof. Gunnar Hartmann

Banush Shyqeriu

London City Hall Foster and Partners Greenery, Water & Waste Multi-Performance The strangely beautiful egg shape of the Greater London Authority (GLA) by Foster and Partners has as much to do with sustainability as it does with architectural design.

The energy strategy for City Hall enables it to run on a quarter of the energy consumed by a typical high specification office building. This is achieved not only through the use of ecologically sound, passive environmental control systems, but also through the shape and alignment of the building. The building's form and geometry has been generated as result of thorough scientific analysis, aiming to reduce both solar gain and heat loss via the building's skin.

The access ramp corkscrews its way through City Hall. The ramp's design—a box that carries concrete treads contributes to the Assembly chamber's superb acoustics.

This space has such fine acoustics that speakers don't need microphones; even softly spoken conversation is audible on the upper levels of the ramp.

The acoustical analysis of the debating chamber in City Hall, London by Arup

McGrow Hill Construction, Architectural Record 02/2003 Fabricators, Cambridge Galleries November 11, Greenery, Water & Waste Digital 2004 - January 30 2005

DIA - Architectural Theory WS08/09 Prof. Gunnar Hartmann

Banush Shyqeriu

London City Hall Foster and Partners Greenery, Water & Waste

Greenery/Landscaping

Waste & Nutrient-management intake / outtake of water & waste 'Electrical consumption is reduced by avoiding refrigeration and using cold ground water to aircondition the building. The water is extracted from the water table beneath London through two bore holes and used to cool the building and then used in toilets and for irrigation savings on mains water'.

The landscaped area immediately around City Hall is the first of a series of integrated public spaces which are being opened in phases.

In the summer, comfortable internal temperatures are maintained by chilled beams. The ground water is pumped to a height of 410 feet at a temperature of 53 to 57 degrees Fahrenheit from the aquifer below the building via two specially drilled boreholes. This cold ground water is also used directly in the cooling coils of the air-handling units to cool the fresh air entering the building. Following circulation, the ground (aquifer) water is used to flush toilets before being discharged, further reducing water consumption.

Greenery, Water & Waste McGrow Hill Construction, Architectural Record 02/2003

DIA - Architectural Theory WS08/09 Prof. Gunnar Hartmann

Banush Shyqeriu