Hugh Battersby is seeking to put the building, which is already Grade II listed, on the radar of Historic England in the hope it will be included in the heritage body's At Risk register.
He says there has been speculation that the building may have been the gate house for the original Ellesmere Water Gate.
The three-storey, four-bedroomed property at 2 & 4 St John's Hill is for sale with a guide price of £70,000. The agents' property details say it needs complete renovation and restoration with potential to become a "super town house." Viewings are being restricted due to the property's condition.
Mr Battersby, who lives in Cross Street, has sent emails to Historic England, Shropshire Council, Ellesmere Society and Ellesmere Town Council to draw the building's attention to them, and saying it is in poor repair.
"The building should be on the At Risk register," he says.
In his email, he says: "I hope that you may be able to keep a watching brief on this unfortunate building and that it can be properly restored and saved from further damage."
He adds: "Many buildings in Ellesmere have been listed purely for townscape reasons. This building is, however, one of the tiny handful of half-timbered buildings remaining in the town.
"Not only that, but it is the only half-timbered building remaining on the south side of St John's Hill, no doubt because it was a long-established butcher's shop, closing only in about 1980. The other buildings have been refronted in brick in a more fashionable style."
Mr Battersby also has a past personal connection, as he says: "I rented the two top floors of the building, then set up as a separate maisonette with its own modern staircase, for some four years, about 20 years ago.
"At that time, while the ground floor shop was vacant and the property offered for sale, the building was in a good state of repair. Shortly after I left, I believe that the property was hit by a large vehicle and Shropshire County Council erected two stout bollards on the Birch Road frontage to avoid a recurrence.
"I have reason to believe that the subsequent repairs may have been surface rather than structural."