<P> For series 12, the judges' houses round was given a new tweak: the contestants perform for their mentors in the scheduled destinations as usual, but only find out whether or not they are through to the live shows during a live decider in front of a studio audience of friends and family . Judges' houses returned to its previous format in being entirely pre-recorded at the locations for series 13 . </P> <P> The selected finalists (either 9, 12, 13 or 16 acts) move into shared accommodation to take part in the show . The house accommodates both contestants and TV production staff and footage from the house is often used in spin - off show The Xtra Factor . In 2009 the house, in West Heath Avenue, Golders Green, received significant press coverage when it was mobbed by fans, leading to the police being called . This led to concerns by the neighbours of the 2010 house in Hyver Hill, Mill Hill that it would receive similar attention, with a local farmer worried his land would be damaged, but local businesses were said to be looking forward to increased trade . The 2011 residence, Connaught House in Hertford Heath had cameras installed for filming . In 2012, the finalists stayed at the Corinthia Hotel in London . </P> <P> The finals consist of a series of two live shows, the first featuring the contestants' performances and the second revealing the results of the public voting, culminating in one or more acts being eliminated . Celebrity guest performers also feature regularly . These live shows were filmed at Fountain Studios in Wembley, London from series 1 to 13 . In series 1--5, both live shows were broadcast on Saturday nights . In series 6, the results show moved to Sunday nights . In series 1, nine acts were put through to the live shows, increased to 12 in series 2 . In series 7, following the addition of four wildcards, it increased to 16 . In series 8, the judges selected four acts each to go through the live shows, without the inclusion of wildcards . Then in series 9, it reduced back to three each, but one wildcard was added, meaning there were 13 finalists . Series 10 reverted to 12 finalists . Series 11 initially did the same, but the addition of four wildcards in the live shows brought it back up to 16 finalists; but with the wildcards chosen by a different judge instead of their category's mentor . Series 12 used the same format as series 9, in which each category had three acts before one wildcard was added . For series 13, it returned to just 12 finalists, with no wildcard twist (like in series 10), although wildcard acts in each category were selected prior to judges' houses, each judge picking for another judge's category . Series 14 also used the wildcard premise as series 7 and 11, but added a twist in which the public voted for one act in each category to progress to the live shows . </P> <P> The show is primarily concerned with identifying a potential pop star or star group, and singing talent, appearance, personality, stage presence and dance routines are all important elements of the contestants' performances . In the initial live shows, each act performs once in the first show in front of a studio audience and the judges, usually singing over a pre-recorded backing track . Dancers are also commonly featured . Acts occasionally accompany themselves on guitar or piano . </P>

Where is the x factor live shows filmed