The new owner of the property in Saanich, a northern suburb of Victoria, was renovating the house and had recently switched from oil heat to electric, the Canadian Broadcasting Corp. reported.
Owner Terry Phillips said he had disconnected the underground tank and wasn't there when a tanker truck pulled up and pumped almost 80 gallons of oil into the disconnected tank.
"They got the wrong address," he said. "They filled up the tank. It went into the ground."
When the accident was discovered, it was significant enough to alert British Columbia environmental officials, the report said.
Hazardous materials contractor David Rogers told the CBC it was clear cleanup couldn't happen with the house standing.
"Quite often we can dig under the house and support it with concrete," he said. "Because of the way it is, and the underground oil tank here, we could not support the house and save it."
The oil company's insurance is responsible for costs, the report said.