Robert Fidler, 63, was ordered by the Planning Inspectorate to demolish Redhill, England, castle at the end of a six-year planning battle, The Sun reported Monday.
Fidler concealed the castle, which includes ramparts and canons, behind a 40-foot-tall stack of hay bales and tarpaulin for four years in an attempt to circumvent planning rules using a rule stating property built without permission but unchallenged for four years could not be "enforced against."
However, the Reigate & Banstead Council said in 2007 Fidler's castle would not be granted retroactive planning permission because he "set out deliberately to deceive" the council.
"His actions in constructing the dwelling house behind a wall of straw bales, and then living in the building for over four years before the bales were removed, was intended to conceal the building and its use from the council's knowledge and thus prevent any enforcement action being taken before it was too late," Inspector Sara Morgan wrote in the council's report.
Fidler previously said he would take the battle to the European Court of Human Rights, if necessary.
"This house will never be knocked down. This is a beautiful house that has been lovingly created. I will do whatever it takes to keep it," Fidler said.