Key facts about City Hall

Height of the building:

45m

No. of floors:

10 floors above the ground

Gross floor area:

185,000 sq ft/18,000 sq m (approx)

Net lettable floor area:

130,000 sq ft/12,000 sq m (approx)

Steelwork:

Structural frame - 2100 tons
Reinforced - 1950 tons

Concrete (core):

13,100 sq m

Cladding:

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

Heat insulation:

Average value= 0.7-0.8 W/m_.k

Angle of glass front inclination:

31 degrees

Diameter of circular glass facade:

45m

Environmental strategy:

Windows open for natural ventilation, bore hole water cooling, heat recovery, displacement ventilation system, no chillers required

Energy consumption:

Energy consumption for the GLA's environmental systems is less than half levels in DETR good practice office guide.
The radical shape of the building minimses the surface area (approx 25 per cent less than an equivalent rectangular building). It is self shading and the high performance facade ensures excellent energy efficiency.

Electrical consumption:

Greatly reduced as a result of using cold ground water instead of refrigeration to air condition the building. Saving use of mains water, the water is extracted through two bore holes from the water table beneath London and is used to cool the building and is then used for flushing the toilets.

Architect:

Foster and Partners

Construction Managers:

MACE

Structural, services, facade, fire, communications and acoustics engineers:

Arup & Partners

Cost consultants:

Davis Langdon & Everest and Mott Green & Wall

Landscape architects:

Townshends