What is a Listed Building?
A listed building is one of special significance. All buildings built before 1700 which survive in anything like their original condition are listed and most buildings built between 1700-1840 are also listed. Normally a building has to be over 30-years-old to be eligible for listing.
Grade I – Buildings of exceptional interest. 2.5% of listed buildings are Grade I.
Grade II* – Buildings of more than special interest. 5.5% of listed buildings are Grade II*.
Grade II – Buildings of special interest. 92% of listed buildings are Grade II.
Little Cassiobury is a grade II* listed building, one of the only three grade II* listed buildings in Watford, the other two being Frogmore House and The Mrs Elizabeth Fuller Free School.