London housing

A friend's moving over from Ireland on Tuesday, but has unexpectedly been shat on from a great height by his expected landlady who has given the room he'd promised to take to someone else.

Anyone know of any possibilities? 'Cheap' would be good, 'not a hell hole' would also be good. East London would be useful, but not obligatory. He's a non-smoker, possibly lapsed but certainly well-behaved.