Police say the fire started in the basement of a home in the 5600 block of Rupert Street, just before 5 a.m. PT Friday morning. No one was home at the time.
The family of six, who had been living at home, moved out after the first fire broke out on February 20. Three hours before that, fire crews had responded to a garage fire just metres away.
Fire investigators say the blazes are suspicious but they have yet to determine who is behind them.
"At this point in time, I can't tell you that the three fires are connected,” said Capt. Gabe Roder of the Vancouver Fire Department.
"We can somewhat put the original two fires together. All I can tell you is the investigation is ongoing."
Vancouver police said neighbours should immediately call for help if they see strange behavior in the area.
"There is nothing to suggest at this point that those fires are linked in any way. Arson is one of those crimes they can be difficult to solve,” said Const. Brian Montague.
"We rely heavily on the public to help us solve them."