The voting process can be done via telephone or online. When the final week arrives, the viewers vote for which of the remaining housemates should win the series, and the housemate with the most votes becomes the winner. The prize fund has varied throughout the series, ranging from £50,000 to £150,000. During their time in the house, housemates are given weekly tasks to perform. The housemates wager a portion of their weekly shopping budget on the task, and either win double their wagered fund or lose the wagered fund depending on their performance in the task. The housemates are required to work as a group to complete their tasks, with the format of the tasks varying based on the number of remaining housemates. Throughout the series, some housemates have been given secret tasks that must either be completed individually or with a small group; failure to do so can result in the housemate being nominated or punished in the house. Should the housemates run out of the food provided for them, an emergency ration is available to them. The housemates are forbidden from discussing nominations, and doing so could result in punishment. The format of the series is mainly seen as a social experiment, and requires housemates to interact with others who may have differing ideals, beliefs, and prejudices. Housemates are also required to make visits to the diary room during their stay in the house, where they are able to share their thoughts and feelings on their fellow housemates and the game. House For the first two series, the house was located in Bow, London, near the 3 Mills Studios. After planning permission expired in 2002, Newham London Borough Council ordered the complex to be returned to a natural habitat. The house had been located at Elstree Studios, Borehamwood, Hertfordshire since Big Brother 3 in 2002. Following a break in during the second series, it was reported that security had increased to the point that the house was more secure than Buckingham Palace. The interior of the house has changed each year, reflecting a certain theme or twist in the game. The fifth series, which featured stricter rules and consequences, featured a harsh colour scheme and a claustrophobic setting. The third series featured a "Rich and Poor" twist, thus a row of bars was placed in the centre of the house to divide the housemates. The diary room features