The spare room subsidy allows one bedroom for each person or couple with the following exceptions.
Foster carers will be allowed one extra room, as long as they have fostered a child or become an approved foster carer within the last 52 weeks.
Children under 16 of the same gender are expected to share.
A disabled tenant or partner who needs a non-resident overnight carer will be allowed an extra room.
Children under 10 are expected to share, regardless of gender.
Parents with adult children in the armed forces (or reservists) who normally live with them will be able to keep the bedroom when they are deployed on operations.
Department for Work and Pensions