Magical Mechanics

A gigantic bird of prey could turn out to be the architectural sensation of Dubai World Expo 2020, which will open on 20 October of this year. Star architect Santiago Calatrava is constructing a 15,000-square-metre covered expo pavilion for the United Arab Emirates (UAE) whose silhouette is reminiscent of a raptor in flight. And in fact the immense flight study will actually be able to move its wings thanks to a complex design. The futuristic Falcon Pavilion is an homage to falconry, which is closely associated with the history of the UAE, host of the Expo. “The pavilion will be one of the Expo’s greatest icons,” says Reem Ebrahim Al Hashimy, United Arab Emirate Minister of State for International Cooperation and Director General of Expo 2020 Dubai. Of course the building won’t actually be able to lift off. But the structure, designed according to LEED Platinum standards, is replete with kinetic refinements.

“Kinetic” primarily means relating to or resulting from motion. Engineers all over the world are developing sliding, rotatable and foldable building parts with individual functions for the interiors and exteriors of buildings. This basically produces magical effects in the otherwise static world of architecture. The most prominent examples are large cultural and sports structures. The Shed, a cultural centre in New York City that opened in April 2019, features an enormous membrane forming a shell that can be telescoped out using rails. Expanding the impressive outer shell skin over the eight-story base building creates an additional roofed space on the side that can be used for major events. No less spectacular is the Fosun Foundation arts and cultural development centre in Shanghai. The building is surrounded by a movable curtain-like facade. Three layers of bronze tubes of different lengths, resembling giant pieces of bamboo, create a veil that moves vertically around the outside of the building, altering its shape.

Dynamic forces allow buildings to move

Kinetic architecture is also making a mark in the area of sports. For example, the technical showpiece of the “Auf Schalke” football stadium is a slide-out pitch made of 11,000 tonnes of reinforced concrete. It is used to move the grass playing field in and out of the stadium. And the Mercedes-Benz Stadium in Atlanta features an impressive bionic roof. The structure is made of eight monumental triangular “petals”. They slide along rails and can be opened and closed like a camera iris.

Kinetics, which comes from the Greek word “kinesis” for motion, is a discipline of technical mechanics used by architects for many different building functions, not just for projects that evoke superlatives. This always involves being able to make parts of buildings adaptable, which requires the ability to control the movement of structural elements, including the forces acting on them. Achieving that type of flexibility is no easy matter for massive structures.

A building is also referred to as an “immovable asset”, the very name of which implies standing still, without changing shape, “cast in stone” so to speak. Structural engineers ensure that all forces are in balance and ideally there is no movement. However, a combination of structural engineering and kinetics can fulfil the prerequisites for allowing dynamics – a branch of mechanics concerned with the motion of bodies under the action of forces – to be used in buildings as well. Kinetic buildings are considered to be highly adaptable thanks to their changeable designs. This offers many advantages. Adaptive buildings can alter their own structures, for example to respond to seasonal conditions or incident light, to meet users’ needs for space or – as in the Falcon Pavilion in Dubai – to serve as a national symbol. Of course, sliding, pulling, and lifting or moving, folding, and rotating can be a lot of fun, offering infinite creative potential, as shown by some examples of residential construction.

The Quadrant House in Poland, for example, has a roofed terrace that automatically moves across the lawn to follow the sun. The terrace swings out a full 90 degrees, performing several functions simultaneously: extending spaces, regulating sunlight, and giving shade. “Moving architecture is never just a gimmick and is always employed as a means to an end,” says architect Robert Konieczny of KWK Promes. The days when residents had to adjust to a static building and any changes required a new design seem to be over. This philosophy has been radically implemented in the Sliding House in the UK. The London architectural firm dRMM goes so far as to speak of a “denial of static architecture”. The private client/builder found local planning parameters to be too boring, so now a 20-tonne larch shell 16 metres long spans recessed railway tracks. The mobile roof/wall enclosure provides warmth in winter and shade in summer and can also convert interior spaces into open-air living areas.

Smart building envelopes that move

Kinetic buildings are gaining converts because they upgrade the appearance of the property and also offer additional functions to improve user comfort. Kinetics can also make a major contribution to the sustainability of buildings. Movable facades with a climate control function serve as smart building envelopes that interact with external conditions, thereby improving the energy footprint. “Between digitally controlled mechanical systems and self-actuating ‚smart materials’, an enormous range of proposals is being developed these days,” says Philipp Molter, Professor of Architectural Design and Building Envelope at TU Munich.

The Al Bahr Towers in Abu Dhabi are a good example of this. The distinguishing feature of the towers is the movable translucent facade whose triangular elements automatically open and close. Each tower has some 2,000 of the umbrella-like translucent glass elements. The triangles, which are coated with fibreglass, are programmed to respond to the movement of the sun as a way to reduce solar gain and glare.

Even with intensive solar radiation and outside temperatures up to 50 degrees, they make it possible to avoid the use of heavily tinted glass, which reduces the need for artificial light and interior blinds, and lets more light in, offering better views. The smart facade is controlled by a building management system. According to the architect Aedas Interiors, energy consumption in the towers has been reduced to about half that of conventional structures.

Climate change drives energy efficiency

It is likely that efforts to increase energy efficiency and the need for climate action will be the primary drivers of kinetic architecture in the 21st century. The development of artificial intelligence, robotics, and computer- and data-based systems will no doubt promote this. In any event, there is no lack of proposals. One of many conceptual ideas is the futuristic Dynamic Tower proposed by architect David Fisher. His 420-metre skyscraper would have 80 individually revolving floors with wind turbines hidden between them. This unconventional high-rise was originally supposed to be opened by the time of the Expo in Dubai, but we will just have to wait when and if this movable architectural wonder will be completed.

By Elke Hildebrandt