Nursery is already mapped as part of the building. Photo at https://historicengland.org.uk/listing/the-list/list-entry/1084327?section=comments-and-photos shows an arch sign at the mail entrance. Name on the sign is presumably Dorset Hall but resolution is insufficient to be sure. 

If there's no longer an education office signed there, the name of the building itself should probably be changed to whatever the arch says.