A heritage architect has called for the remnants of a historic inner-Sydney building to be saved after a fire last Thursday gutted the Federation warehouse.
Hector Abrahams said the former R.C. Henderson hat factory, which was built in 1912, was constructed from bricks made to withstand high temperatures.
"It's highly likely that quite a bit of the walls will be structurally viable," Mr Abrahams told the ABC.
Demolition works are set to begin today, but it is unclear how much of the warehouse will be torn down.
"Once the site is rendered safe, further assessments will be undertaken by contactors and engineers to determine whether the remaining structure will be salvageable," NSW Police said in a statement.
Mr Abrahams has worked on restoring fire-damaged buildings before.
He said the walls of the factory on Randle Street were at least half-a-metre thick at the base and designed to hold themselves up.
"They're not cavity, they're solid wall.
"If you were going to have a structure survive a fire and have a chance at being rebuilt, it would be an early 20th century warehouse in Sydney."
Mr Abrahams said hardwood, which frames the building, would not burn easily.
"But once you do get it to burn, it's going to burn very hot."
Mr Abrahams said cold firefighting water hitting hot bricks could cause "significant issues with the bricks but not necessarily."
He added that pollutants from the factory's history as an industrial building have helped it burn.
The building is listed as a structure of local heritage significance on the Sydney Local Environmental Plan.
The former factory makes "an important contribution" to the streetscape and "represents the influx of industrial development" in Surry Hills during the early 20th century, according to a statement of significance on the State Heritage Inventory website.
The entrance is described as an "uncommon example of decorative brickwork for Federation warehouse style buildings in Surry Hills".
"My inclination would be to have the building seriously considered for retention," Mr Abrahams said.
"We shouldn't just toss buildings aside anymore. We should take them seriously — even those that have been through fires.
"I'd like to see it saved, if it could possibly happen."
The City of Sydney Council would not say whether parts of the building deemed safe to remain standing will be protected from demolition.
"The demolition of the site is being directed by NSW Emergency Services, with safety being the top concern," a City of Sydney spokesperson said.
"Fire and Rescue NSW would be best place [sic] to provide details on the extent of the demolition."