[QUOTE=Ross;174108]That should be your main priority before you submit an application. It won't matter if he hasn't lived there very long as long as the accomodation is suitable for a couple with three children, his tenancy is secure and he has a letter from his landlord to prove this.
What are the ages and sex of the 3 children, because this can make a difference as to whether the ECO will decide that the accomodation has enough bedrooms. I don't know the exact details of how they work this out, but it usually means that children above a certain age should not be expected to share a bedroom with another child of the opposite sex.
Iain.