law: 83. Demolition, etc., of buildings.
  If any building is wholly or partly demolished or destroyed or otherwise deprived of value, the Board may, on the application in writing of the owner or occupier, remit or refund such portion of any tax assessed on the annual rateable value thereof as it thinks fit but no remission or refund shall take effect in respect of any period commencing more than two months before the delivery of such application.