The owners of the development company, John Hoffman and Steve Sells, weren't available Wednesday. Their attorney didn't immediately return a call.
The conservancy found a potential buyer who offered more than $2 million, a tidy $250,000 profit for less than three months of ownership, but it was rejected, Mahoney said.
With time ticking down to the expiration of the demolition permit on Thursday, the developers approached the city.
"When they brought this issue up, there was five days left under the permit and they said, 'Well we've got to do something or we're going to lose it,'" Mahoney said. "And we said fine, let's kick the can down the road because there are offers coming in to purchase the property that may solve all of this for everyone."
Mahoney said other buyers have contacted the city, even as the historic designation goes forward.
"I'm pretty confident that given sufficient time, the home will be purchased by someone who will not only consent to historic landmark status ... but will also consent to a perpetual conservation easement," Mahoney said. "The mayor is a strong proponent of historic presentation of all kinds, but this building in particular is an architectural jewel. It would be destroying a Rembrandt or a Picasso."