 After the collapse of the Cardiff Bay Opera House scheme , a new project , the Wales Millennium Centre , met with more success . The necessary <unk> and funding were obtained , and work began in 2002 on a new multipurpose arts centre on the Cardiff Bay site . The centre included a 1 @,@ 900 @-@ seat theatre , which , among other uses , became WNO 's home base from 2004 , with its own rehearsal space and offices in the complex . 
