As these shocking pictures show, the couple's privately owned home in Millroad Drive, in the Calton area of Glasgow, is collapsing.
The residents raised the alarm around a month ago, to say that cracks were appearing in their back garden area and inside their house.
But the crater got progressively worse - and the couple were advised to get out of the East End property just before Christmas.
They moved into temporary accommodation and are in discussions with insurance advisors, the city council and Scottish Water, to decide what to do next.
At the side of the property, stretching to the back garden, safety fencing has been put up, while engineers are regularly inspecting the site.
Due to the state of the building's structure, there are fears it will need to be demolished.
But that would affect neighbours' homes adjoined in the row of terraced housing, which was built in the early 1980s.
Nearby residents told of their shock at the collapse.
One neighbour of the couple, who asked not to be named, said: "It's unbelievable how much the house has sunk in such a short time.
"You could see the walls and the garden starting to crack about five weeks ago.
"But then it just got worse and worse, and now everything is lopsided.
"The couple had to leave and a lorry came to pick up all their belongings.
"We've been told it's unsafe to go anywhere near it but if they demolish the house they might have to demolish other homes too."
The subsidence could have been caused by several factors.
There are concerns that there is an issue connected to water ingress.
Scottish Water said the movement had damaged their sewer system.
They are carrying out an investigation in a bid to establish what caused the subsidence.
It is understood there is a network of old rail tunnels underneath parts of the city's East End which date back to the 1800s, which may be a contributing factor.
The road beside the property and a bulging wall have also been sealed off by the council for safety reasons.
A council spokesman said: "We are aware of subsidence in the area, which has forced the closure of an adjacent residential road.
"Access to neighbouring properties is being maintained via an alternative route.
"The root cause of the subsidence has yet to be established, but a number of property owners and agencies with infrastructure in the area are currently carrying out investigations.
"While the council is clear that it does not have any infrastructure that could have caused the movement, it will support that ongoing work."
A Scottish Water spokesman said they were continuing to assist with the probe.
He said: "This ground subsidence caused damage to one of our sewer manholes, although customer services remain unaffected.
"We will continue to work with the council and other partners to establish the root cause of the problem."
A tenant of Thenue Housing lives in the property adjoining to the affected building.
A spokesman for the housing group said they were in talks with Scottish Water and the council because the incident affected "a terraced, owner-occupied property next to one of our homes occupied by a tenant".
He said discussions with the tenant were underway to see if he could remain in the property.
The spokesman added: "At all times the safety of our tenant and of the neighbouring owner occupier is our prime concern.
"We are talking to our tenant at the moment about whether it will be possible to remain in the property while investigations are under way."
It is not the first time there has been serious subsidence in the area.
Around two years ago a lane behind the homes in Millroad Drive collapsed creating a 7ft deep hole.
The council and Thenue Housing Association were made aware of the incident and the ground repaired.
However, a council spokesman said engineers did not believe that incident was connected to the sinking home.
A man, who lives beside the lane, said: "It was unbelievable when it happened.
"The lane was there one minute and then it was gone.
"We're worried that all the houses are sinking."