People who live near a building that was gutted by a massive fire in downtown Halifax on Sunday have been told their homes aren't safe and they need to find somewhere else to stay on their own dime.

"I don't know, I seriously don't know where I'm going," said David Ballum-Heftka, whose home is surrounded in yellow caution tape.

David Ballum-Heftka says he's not sure where he's going to stay after being told his home is at risk. (CBC)

He and his neighbours were told to leave Sunday while Firefighters worked to put out the major blaze next door.

At the end of the day, fire crews told them it was safe to go home.

But now, it's not.

Phil McNulty, with Halifax Regional Fire and Emergency, said an engineer looked at the site Monday and determined the building is too unstable and the back wall of the building could come down on the nearby townhouses.

"The fire service doesn’t employ structural engineers. When the insurance company arrived on scene today they brought a structural engineer to determine whether or not it was safe and after the engineer reviewed the scene, it was determined that it really was a potential issue," he said.

Unless their own insurance will cover a place to stay, residents have been told they need to pay out of pocket for their accommodations or stay with friends and family.

Residents won't be able to go home until the wall is demolished.

"Due to the size of the fire, the amount of debris that's in the building and the precarious nature of the geography, they're going to have to work from the west side and pull all the debris away before they can address the wall — and it's going to be very slow going," said McNulty.

"They hope that it will be done in less than two weeks but that's just a time line that they've given to the residents to sort of prepare them for the worst."