The Gherkin by the Pritzker Prize Winner – Norman Foster

What happens when you infuse ecology with modernity and high-tech design? You begin to think about the well-being of the users and seek to lessen negative impacts on the environment. Your aim becomes minimizing wastage, reducing the usage of non-renewable resources, and building a healthy environment. In short, you lead toward sustainable innovation. And the architectural marvels similar to Gherkin designed by architects like Norman Foster prove just that!

Let’s take 30 St Mary Axe for example. This tower has a dramatic appearance and is popularly nicknamed “the Gherkin” due to its resemblance to that particular vegetable.

Apart from its distinctive form, 30 St Mary Axe manifests a progressive environment-friendly approach with its aerodynamic design, ventilation, automatic insulation, and natural lighting. As a result, this unmistakable building has won numerous awards for its design and energy-saving features. 

• Name: 30 St Mary Axe (The Gherkin)
• Location: London, England 
• Architects: Norman Foster, Ken Shuttleworth, Ove Arup & Partners
• Construction Company: Skanska
• Architectural style: High-tech, Neo-futurism, Postmodern

In this article, we will take you along on our journey to explore the design aspects of this unusual building. 

Design Principles of Norman Foster

Lord Norman Foster of Thames Bank is a British architect who is renowned for his high-end modern buildings made of glass and steel. His earliest works involved technically advanced structures that were enveloped by a lightweight shell.

The Pritzker Prize winner established himself as one of the world’s leading high-tech designers. By including atria or mini green spaces in his futuristic designs, he rendered a smooth dynamism between inside and outside spaces. He also shifted intrinsic components like elevators to the exterior of the building to create an open plan and make them easily accessible.

Being one of the pioneers of high-tech architecture, his design philosophy involves adaptability, integration, flexibility, technology, and regeneration. He believes architecture is the expression of values and all his works reflect these principles.

Features of The Gherkin

Constructed between 2001 and 2004 at the epicenter of London, this 40-storeyed  headquarters of the Swiss Reinsurance Company is the first ecological skyscraper in the commercial capital of Great Britain. Having been built on the grounds of the Baltic Exchange which was destroyed in the 1992 IRA bombing, the location holds an emotional and cultural significance. 

• With a circular plan, the Gherkin has an increasing diameter till the middle which then tapers towards the top. The varying diameters of 49 meters at the base, 56.5 meters in the middle, and 26.5 meters at the top are what result in its distinct appearance. 

• The building’s aerodynamic shape helps in generating differential air pressures and reduces wind load on the structure.

• The light wells allow natural ventilation which curtails the use of air conditioning, acts as a good fire escape strategy, maximizes the penetration of natural light, and provides a sustainable indoor environment. 

• An interconnecting network of air ducts is used on each floor which extracts warm air in summer and uses passive heat from the sun for warming in winter.

• Abundant light sensors prevent the unnecessary use of artificial lighting in interior spaces.
• The dining areas at level 38 and the restaurant at level 39 offer a stunning view of St Paul’s Cathedral, whereas the bar at level 40 offers a beautiful 360-degree view of the city.
• The walkways around the building house a range of places to shop, eat, and socialize.

Design And Planning

The shape and geometry of the Gherkin emphasize a series of progressive curves and openings that correspond to forms available in nature like cucumber or pinecone. However, Norman Foster was inspired by the structure of an airplane.

This 180-meter-high tower is essentially an elongated curved shaft that breaks the traditions of stereotypical box-like buildings. The building is tapered at the top and the bottom to let in the maximum amount of daylight and enhance connections with the surrounding areas. 

• The diagrid geometry of the external steel framework with glass encasing makes the structure incredibly strong, light, and flexible.

• The building’s radial geometry allows the possibility of an orthogonal arrangement of desks, bathrooms, and stairs in the central portion. Only 3% of the spaces are closed as the majority of the rooms have an exterior view.
• The entrance lobby connects the interior scheme to the outside experience with the help of 7 meters high extruded aluminum panels. Plus, the building includes lift lobbies to connect all the interior facilities. 
• The circular plan also allows the peripheral area to be refurbished as a public plaza with landscaping and low stone walls acting both as a public seating and site boundary.

Material And Construction

The Gherkin stands atop a foundation of 333 piles with 750mm diameter that are bored directly into the London clay.  

Almost 10,000 tons of steel and 24,000 square meters of glass were used in the construction of Gherkin’s diagrid exterior. 

The diagrid encasing is made of aluminum-coated tube steel formed by two inverted V’s covering the height of two floors. Whereas the central core is surrounded by a grid of diagonally braced steel.

The exoskeleton is cladded with 5500 diamond-shaped glass panels. that have a ventilated cavity containing solar-control blinds sandwiched between a double-glazed outer layer and a single-glazed inner screen. These cavities serve as buffer zones to reduce excessive heating or cooling. The light wells that spiral up the tower are also double-glazed with grey-tinted glass and a high-performance coating.

In a Nutshell

Architecture has the proficiency to teleport observers to a timeless dimension by making ingenious use of space. Norman Foster was successful in establishing the Gherkin as a technologically, environmentally, and architecturally radical building, which is an archetype of responsible sustainable practice. By strengthening the relationship between environment and technology, 30 St Mary Axe remains a visible token of innovation for both architects and patrons around the world.

By Sreyoshi Dhali

While finding her solace in silence and everything mundane, Shreyosi prefers to untangle the chaos inside her head and makes an effort to paint scenarios with words that keep her awake at night.