City staff are recommending four heritage buildings on the site of the proposed Frank Gehry condos be protected from possible demolition, a position that could put the brakes on the three giant 82-, 84- and, 86-storey towers.

In a report due to be presented at Toronto Preservation Board meeting, staff say knocking down the Eclipse Whitewear, Anderson, Gillett, and Reid buildings, which is part of the current application, would be "an unacceptable loss" for the city's heritage.

"The re-zoning application as currently submitted contemplates these four demolitions ... and that is something that is not considered to be a reasonable threshold," says Mary MacDonald, acting manager of Heritage Preservation Services. "It doesn't say that an application that does a better job of heritage conservation is impossible. This particular strategy is not a good one from the city's perspective."

Peter Kofman, President of Projectcore Inc., the development company behind the project, thinks the loss of the buildings would be mitigated by the acquisition of Gehry's design.

"We think we will get a much better project without the retention of these buildings and it's a much more exciting project that way," he says. "Certainly that's our intention and we're going to proceed in that manner."

The Mirvish+Gehry project, unveiled at the Art Gallery of Ontario in October 2012, would see all of the buildings between the Royal Alexandra Theatre and John on the north side of King demolished for a new art gallery, an OCAD satellite campus, and a mix of residential and retail properties.

The heritage buildings, all built in the first 15 years of the 20th century, are one of the few remaining pieces of King West's manufacturing history. As late as the 1960s, boxcars and factory workers were a common site in the area now known for its theatrical offerings.

City staff and representatives of Mirvish+Gehry and the developers are due to discuss the report at tomorrow's preservation board meeting.

The heritage staff report will eventually form part of the city's broader official stance on the Mirvish+Gehry application. Council will have final say on whether the buildings stay or go, though an appeal has already been launched at the Ontario Municipal Board because the city failed to respond within the required timeframe.

Would Toronto be missing a trick by denying the demolition of the warehouses? Should the city honour the buildings' protections under the Ontario Heritage Act?

Chris Bateman is a staff writer at blogTO. Follow him on Twitter at @chrisbateman.

Images: Mirvish+Gehry, Projectcore Inc.