Mike Paddington had permission to convert the bedroom after his 33-year-old son, who has been severely disabled since he was a baby, contracted a life-threatening illness last year. He installed the separate toilet and wash basin for his son's carers and the rest of the family to reduce the risk of infection, in accordance with the law. However his Cornish housing association landlords say the toilet should still be classed as a bedroom - leaving the family liable for an extra £700 in rent a year.