Download case study 5: swiss re tower, uk

CASE STUDY 5: SWISS RE TOWER, UK
“MOTIVATED OWNERS PROVE TALL BUILDINGS
CAN EMBODY SUSTAINABLE DEVELOPMENT”
Project Name:
Location:
Sector:
Architects:
Year of Completion:
Rating:
Barriers Overcome:
Example of:
30 St. Mary Axe
London, UK
Commercial Building / Tall Building
Foster and Partners
2004
Stirling Prize
Small Site Footprint; Cost of New Techniques;
BIOCLIMATIC SKYSCRAPER
ARCHITECTURAL TEAMING
INNOVATION
IN
CHOOSING
APPROACH”
“BIOCLIMATIC
PROJECT OVERVIEW:
The headquarters of Swiss Reinsurance Company (Swiss Re) at 30 St. Mary Axe, downtown
London, was a significant addition to the city skyline. This 822,363 s.f. building stands 40
storeys high and is the second-tallest building in the area. It was the first “environmentallyprogressive tall building” and won the coveted Stirling Prize1. The building has a façade that
allows fresh air and daylight infiltration (allowing for what is known as “external awareness”).
The building’s most distinctive feature is the shape that Londoners call the “erotic gherkin”. Its
cylindrical shape allows for the demands of the site as well as aerodynamics.
By using
Parametric Modeling2, the curved surfaces were able to be rationalized into flat panels that
allowed economic construction.
POLICY OR PROGRAMMATIC CLIMATE:
European Policies on Energy Efficiency
The European Commission published its Directive to improve the energy performance of
buildings (COM/2001/226 final) in May 2001. (This Directive was an amendment to the Council
Directive 93/76/EEC to Limit Carbon Dioxide Emissions by Improving the Energy Efficiency-SAVE). The SAVE Directive establishes a common methodology for calculating integrated
energy performance of buildings, applies MEPS for new or existing buildings greater than 1500
m2, and certifies new schemes for the thermal performance of buildings (among other things).
European Policies on Environmental Sustainability
Directorate General 11 of the European Commission (DG11) is an awareness approach aimed at
integrating environmental concepts into new housing in Central and Eastern Europe. Guidance is
given through handbooks, information exchange, and co-financing to increase the awareness of
the environmental impacts of large housing estates such as Gallions Ecopark. The “Energy
Efficient Construction Products Regulations” govern building materials and assemblies of all
buildings within the EU. These regulations are primarily concerned with the compatibility of
construction products from environmental and health requirement standpoints. The European
Eco-Label Scheme covers building materials according to their environmental criteria and
although first developed for paints and decorative elements, the Eco-Label has been expanded to
include assemblies. The European Council Resolution of 24 February 1997 on Waste Policy
covers (among other things) construction and demolition waste.
European Financing Mechanisms for Environmental Sustainability
The LIFE EU financial instrument (EEC Regulation No 1973/92) for environmental loan
arrangements has supported demonstration buildings for sustainable building practices.
Overall United Kingdom Policy on Energy Efficiency and Sustainability
In July 2004, Deputy Prime Minister John Prescott gave the green light to a single national
industry Code for Sustainable Building Practice3 as a way of reducing the country’s CO2
emissions. The Code is designed to reduce energy and water consumption in all new
developments by 25% and picks up the recommendations of the Sustainable Buildings Task
1
The RIBA Stirling Prize is named after noted British architect Sir James Stirling (1926-1992) and is a
cash award of 20,000 GBP or $37,922.
2
This modeling is ideal for the study of complex double curvature shapes and was originally used in the
aerospace industry. The final façade is something called a “diagrid” of interlocking elements that provide
enough stiffness for the central core to act as the only load-bearing element.
Building regulations Part “L” relates to energy and all developments must comply with this, by April
2005.
3
Group (SBTG) report on ways government and industry can work together 4. This Code is
presently under scrutiny by RIBA, the House Builders Federation, and CABE (the Commission
for Architecture and the Built Environment).
United Kingdom’s Policies on Energy Efficiency in Residential Buildings
The Building Research Establishment (BRE) annual energy consumption guidelines for
residential buildings are covered under its Ecohomes program. The UK “Building Regulations
1991” govern performance requirements for buildings and Part “L” of these regulations deals
with energy use.
United Kingdom’s Policies on Sustainability
The “Good Practice Guide on Planning for Sustainable Development” is an informational system
that controls the impact of buildings on the surrounding environment.
City Policies on Energy Efficiency or Renewable Energy
In addition to the Energy White Paper, the Mayor of London has initiated a “London Energy
Plan5” that contains a “Green Light to Clean Power” section for use of renewable energy sources.
INNOVATIONS IN PROJECT TEAM CONSTRUCTION:
The decision to “go green” was derived by a team project team of architects, contractors, and
owners along with other partners in the supply chain who worked from the beginning of the
project to advise on the design.
GOALS OF THE PROJECT:
A key objective of this project (from the architects’ standpoint) was to prove that commercial tall
buildings could achieve sustainable development. The key objective (from the Owner’s
standpoint) was to adhere with their ethos of following a common definition of sustainable
development given by the World Commission on Environment & Development, 1997, that was
“to embody development that meets the needs of the present without compromising the ability of
future generations to meet their own needs.”
FACTORS THAT DROVE ENERGY EFFICIENCY:
The motivation of the Owner propelled the energy efficiency of the design.
ARCHITECT’S COMMENTS ON THE MOST IMPORTANT DRIVER TOWARDS ENERGY
EFFICIENCY: “Conceptually, the project develops ideas first explored in the Climatroffice design
with Buckminster Fuller in the early 1970s. The project envisioned office space enclosed within a
freeform glass skin to create a building with its own microclimate. At the time its complex,
double-curved geometry would have been difficult to build. Thirty years later, digital
technologies facilitate the design and construction of buildings such as 30 St. Mary Axe in a
fraction of the time it would have taken in the 1970s.”
STRATEGIES FEATURED:
4
Prescott also suggested that BREEAM ratings and EcoHomes (both operated by BRE) should be replaced
by this new Code to eliminate the confusing array of environmental standards. Critics argue that this code
has been produced by the government to demonstrate its commitment to CO 2 reduction but that by focusing
on water and energy efficiency, the new Code has neglected a full investigation of other methods of CO 2
reduction (for example, in “closed loop” construction wherein disused building materials takes the place of
new materials).
5
Under the “London Plan”.
The building has low-energy lighting, occupancy and motion sensors, double-glazed tinted glass
windows that also act as air exhaust devices, as the air moves between the double-glazing to
reduce the solar radiation. Light wells were also used to allow light to penetrate through the
floors. Owing to its shape, wind loads are not deflected towards the ground (and pedestrians).
Reduced wind loads on the structure and cladding allowed less weight in the structure at the skin
of the building. The shape also improved the building’s transparency and reduced the reflections
on the façade. Swiss Re Tower will surpass the BRE Guidelines for energy use by 25 kWh/m2.
SUSTAINABILITY FEATURES:
The tower uses gas as its primary fuel and the mechanical system is decentralized (with user
demands supplied as needed). The building does not provide private car parking spaces and only
has one parking lot level. (This is possible due to the number of public transit modes that
surround the area). The basement level provides three times more bicycle parking space than the
minimum required by law, plus shower and changing facilities, to encourage use of nonmotorized transport.
LESSONS LEARNED:
 Tall buildings can be built sustainably if there is a favorable policy climate that allows for
such things are operable window and natural ventilation.
 Applying modeling systems from other practices (in this case aeronautics engineering) can
often lead to mass production of building components that otherwise would be prohibitively
expensive.
For more information on this building, contact: Foster and Partners Architects at
[email protected].