The interior of Max's flat and the house that the Man In Street is banging on the door of are in two totally separate parts of London.
Although all the interiors were shot at night, all of the windows in the Max's flat were blacked-out with bin bags. The window Max looks out of is the only one that wasn't blacked.
When kicking the door of the house across the street, actor Dan Poole actually broke the chain it was sitting on.