Beijing National Stadium (BNS) was a joint venture among architects Jacques Herzog and Pierre de Meuron of Herzog & de Meuron, project architect Stefan Marbach, artist Ai Weiwei, and CADG which was led by chief architect Li Xinggang [REF].
In an attempt to hide steel supports for the retractable roof, required in the bidding process, the team developed the "random-looking additional steel" to blend the supports into the rest of the stadium [REF].