Advances in Architectural Engineering
In addition to the modeling technique being state of the art, the finished design also actually moved architectural engineering forward. The Gherkin was built on the former site of the Baltic Exchange, which was structurally damaged on 10 April 1992, by a Provisional IRA bomb. The site is small. The tapered designed allows the building to appear sleeker than a conventional rectangular skyscraper. The slim base and top also reduce reflections and improve transparency, and the floor-to-ceiling windows improve daylight penetration over a conventional building.
The building’s shape also means that it does not need extra reinforcements to add stiffness to resist wind load. The shape of the structure provides the stiffness required. To perfect the shape, wind tunnel tests were performed on a model of the structure. They showed that wind deflected to ground level was reduced and overall wind conditions in the area surrounding the building were improved. The overall stiffness of the structure and the diagonal braces at ground level means that the floor space inside the building is column free.
The energy consumption of the building is 50% less than a typical skyscraper. The building is able to achieve this because of the "diagrid" structure, a grid of diagonally interlocking steel elements used in its construction. Each successive floor is offset so that a spiral atrium is created. Overall six shafts are created by gaps in each floor that serve as a ventilation system. The shafts allow the office space to be insulated with a thin layer of air, similar to the principle of double glazing. Warm air is circulated out of the building during the warmer months and into the building during winter.