 Soon after that Hertfordshire County Council bought Little Cassiobury in 1939 under a compulsory purchase order.They used part of its land to build Watford College and the house was used as an education office for most of the 20th century.Now vacant, Little Cassiobury is listed as "grade II*" and, due to its deteriorating condition, is classed as "at risk" by the English Heritage Buildings at Risk Register.