Dead Set (2008)

It's eviction night at the Big Brother house, but something very strange is happening; the dead are coming alive and attacking the living. When zombies attack all of the audience outside, the Big Brother contestants are unaware of the death outside the fan-proof (and zombie-proof) big brother house until the show's runner, Kelly, comes into the house and warns them of the doom outside. Stuck with even less contact with the outside world, the house-mates must sneak out of the house to get supplies, without being seen by the zombies.