The former Northamptonshire Association for the Blind (NAB) building in Northampton has been demolished.
A large blaze last month severely damaged the building and an investigation by firefighters concluded that it was probably started accidently by vandals.
The building, which was built in about 1860, was going to be converted into 41 one-bedroom and 17 two-bedroom apartments for elderly people.
The work is being carried out by McCarthy & Stone and the newer parts of the building were due to be demolished.
However, due to the damage caused by the fire, the entire structure has now been flattened.
A spokesman for McCarthy & Stone, said: “As agreed with planners and building control the building in question on Welford Road has been demolished as it was deemed too unsafe to enter in its condition after the fire.
“We will now suffer a substantial delay in continuing work in this area of the site as we decide on how to progress the replacement of the building.
“Like many locals in the area, we too were disappointed to see the building gone as we intended to retain many of the features it had to offer for our future homeowners.”