Why Double Up?

It was explained in the Magical Reveal that Pinoy Big Brother has two houses and the housemates have been separated into two groups. The housemates are not aware that there are two houses. PBB also has two pair of identical twins (JP/JM and Toffi/Kenny) who has been tasked by Kuya to live in separate PBB house and they should not reveal that they have a twin brother because they will be switched later. They should also keep it a secret that there are two PBB houses.