The Beijing National Aquatics Centre – of Bird’s Nest and Bubbles (in Retrospect) II

by MENG CHING KWAH

Situated on the western side of the extended axis along the Olympic Green and directly fronting the National Stadium (aka ‘Bird Nest) is the National Aquatics Centre. As the name suggest, it has been the venue for holding swimming, diving and synchronized swimming events during the Olympics. Hence, it is a building about water, for water sports. Yet, the designers – PTW Architects + CCDI + Arup – did not opt for a literal translation of water sports association such as a curvy wavy form. Instead, they went back to the fundamentals and created a deceptively simple piece of architecture which suits the function very well, adopts sustainable design and is extremely poetic and iconic at the same time.

Contextually, the designers had also demonstrated their creativity and ingenuity. When the competition for the National Aquatics Centre was first called, the design of the National Stadium had already been commissioned. Hence, not only must the competitors answer the competition brief of the Aquatics Centre, they must also recognise the imposing and powerful design of the Bird’s Nest with care and skill. How to respond to this elliptical form and yet masculine steel structure? How could the new Aquatics Centre be read as the other symbolic and symbiotic co-existing jewels of the Olympic Green? How to create a contemporary building which represents the pursuance of excellence in water sports while embracing Chinese culture? The designers came up with a masterstroke concept – one that combines the symbolism of a square in Chinese culture with the natural association of water – the bubbles.

On first impression, this fascinating architecture is, actually, a ‘box of bubbles’. The entire building, be it the roof or wall, is covered with bulging ‘bubbles’ of various shapes and sizes. It is as though someone had frozen an entire rectangular cuboid of water soap bubbles and turned it into an architectural form – the Water Cube. This subtle but natural association with water where water is both a structural and thematic leitmotif is indeed a highly sophisticated representation of the actual function of the building. And, like true bubbles, it seems so fragile and light and to be on the verge of bursting with the slightest touch landing on it. It reminds us of younger days when we were all playing with water and soap during our bath and how we were fascinated by the delicate association of the bubbles with one another and how they broke apart and burst so easily. Yet, for all its perceived fragility, it is a strong and sound structure capable of withstanding the seismic forces found in this region of China.

The sublime beauty of the Water Cube is generated by its engineering intent. Other than appearing like water and soap bubbles, the structural design is actually based on the natural formation of soap bubbles, which gives it a random and organic appearance. This ‘box of bubbles’ comprised of steel frames that hold the entire venue together and then clad with ETFE (or Ethylene Tetra Fluoro Ethylene) film both on the interior and exterior. The film is inflated and continuously pumped. Hence, the ‘bubbles’ are actually a series of bloated air pillows, giving them the soft bouncy airy feel, just like real bubbles.

On top of being lightweight and a good acoustic material, the pale blue ETFE film is covered with tiny silver dots that regulate the amount of heat or light passing through to the interior spaces. The different reflective quality of the ETFE skin transforms the look of the chameleonic ‘bubbles’ from a boisterous grey during stormy weather to a metallic blue under direct sunlight. Sometimes, it even reflects the surrounding scenery. When night falls, with the help of LED technology, it emerges as a playful cuboid of water molecules of different colours when illuminated.

Inside the Water Cube, the usual glare associated with a large expanse of skylight roof is not found here. What is instead in place is a soft, muted, atmospheric light that engulfed both the audiences and the swimmers. The ETFE skin has maximized natural daylight while cutting down glare. In addition, it also captures solar energy to heat up the interior spaces and the pools. The ‘box of bubbles’ is like a greenhouse that harnesses solar energy but without the usual trappings of being a heat sink. It looks simplistic but at the same time encompasses state-of-the-art technology and materials that helped to make this building a truly sustainable piece of architecture by being energy efficient. According to the engineer Arup, the ETFE cladding allows more light penetration than traditional glass, which thus resulted in a 30% decrease in energy bills.

As a singular building, the Water Cube is an à la mode architecture which breaks boundaries and defines a turning point in the pursuance of architectural excellence. It ‘demonstrates in a stunning way, how the deliberate morphing of molecular science, architecture and phenomenology can create an airy and misty atmosphere for a personal experience of water leisure.’¹ Culturally, it is deep-rooted in Chinese culture with its square plan relating to the primal shape of the house in Chinese tradition and mythology while also symbolizing the Earth. Collectively, together with the elliptical circular form of the Bird Nest (which symbolizes Heaven in Chinese culture) they have formed a pair of iconic crown jewels at the Olympics Green. A pair that is at two opposite ends, so signifying a duality of Yang and Yin, Heaven and Earth, Fire and Water, Hard and Soft. A pair that is both an architectural marvel and a global icon each in their own right.

Reference
1. Quote from the Jury report of the Official Awards in the 9th International Architecture Exhibition –- METAMORPH for the Venice Biennale 2004.