The developer who smashed down the protected heritage facade of a 1912 building in Potts Point in front of a new apartment block it is constructing has been fined $6000 by the City of Sydney Council as well as being ordered to rebuild the wall.

This will now take place in February next year and the original bricks, taken away and stored off-site, will be brought back and re-used “where possible”, the Singapore-based developer Roxy Pacific has pledged.

The unauthorised demolition of the front of the old Hensley Hall building on Bayswater Road – leaving only two skinny gables propped up by steel girders – provoked an outcry from the local community. The facade’s retention had been a condition of developing a new eight-storey, 44-apartment block called The Hensley on the site.

City of Sydney officers launched an investigation after a Fairfax Media tip-off. Under a 2015 set of penalties, councils can impose fines of up to $6,000 for a minor breach of conditions of consent for local development laws or can prosecute serious breaches at The Land and Environment Court which can impose financial penalties of up to $5 million for a corporation.

A spokesman for the developer, who declined to be named, said: “As part of this adaptive re-use project, which was approved by the council, parts of the facade were removed and will be rebuilt along with the roof structure to maintain its original form.

“However, due to the age of the facade, some dilapidated timbers were discovered and unstable masonry structures, in particular a column, spandrel and parapet, that could not be maintained, and were required to be removed and rebuilt under the instruction of the project’s structural engineer. These will be rebuilt to ensure that the completed building meets the Building Codes of Australia and OH&S requirements.”

Yet a number of local critics are still angry that, even if there were problems with the facade, it was removed without the council and its engineers being contacted and summoned to the site to approve the new works.

Potts Point and Kings Cross Heritage Society president Andrew Woodhouse said: “There was no engineer’s report given to council to clarify or justify or approve demolition, only claims. It was a back-door method of removing items.

“And where they say the original masonry will be used ‘where possible’, that’s just too nebulous. Who decides where it is possible? And if they didn’t comply with the original DA, how can the community be satisfied they will comply with any new arrangements?”

But the developer says the original character of the old building will be carefully preserved and the design of the new apartment block, done by architects Woods Bagot, was approved via a design competition.

“Although much of the facade has been modified, the Bayswater Street facade still reflects elements of the 1920s Federation/Arts and Crafts style,” the spokesman said.

“The principal front form and facade will be reconstructed to an extent that the former character of the architecture of the former boarding house can be interpreted. Balconies on the facade of all the building will be reinstated, notwithstanding that they were infilled in the 1920s shortly after their construction in 1912. The balcony will be reinstated using the design from the original plans located in council’s archives.”

But that hasn’t appeased locals. Pamela Hansford, a justice of the peace who has lived in the area for more than 50 years, says she’s outraged that the company has been fined just $6000.

“What’s that to an international development company – absolutely bloody nothing,” she says. “They probably factored that in right from the start. The situation, which is pretty clear to everybody is that the developer has been allowed to ride roughshod over everything that was agreed.

“It’s no wonder that so many local people are really pissed off about this. We live in this environment, and why can’t they leave just something of the original streetscape that they promised to do? Is that really such a big ask?”

A City of Sydney spokesperson said the development consent required the developer to retain specific elements of the original facade, as recommended and approved by the City of Sydney’s specialist heritage assessment.

But when officers attended the site, “the inspection found that an engaged column, spandrels and parapets between two gabled ends of the Bayswater Road facade had been demolished without approval.

“The demolition of the engaged column, spandrels and parapets constitutes unauthorised building work and enforcement action has been taken. The developer has been issued with a penalty notice.”

A number of new apartments in The Hensley have already been bought off the plan, with prices ranging from $820,000 for a 39-square-metre studio, to $3.75 million for a top-floor three-bedroom apartment.

The developer argues that “the proposed design will maintain the existing streetscape and built character of the area”.

Mr Woodhouse says that’s not correct. “The streetscape will be irrevocably altered in terms of bulk design and materials,” he says. “The built character will be butchered. It is facadism at its worst.”