‘Freak accident’: Rose Bay villa partially collapses during luxury rebuild

For more than a century, the Victorian-era villa known as Hillcrest has stood as a stoic reminder of the past amid an ever-shifting Sydney skyline.

Perched on New South Head Road, a stone’s throw from the shimmering waters of Rose Bay Beach, the heritage-listed landmark survived two world wars, the Great Depression, and the steady march of urbanisation.

But in a matter of seconds on February 12, a chapter of that history came toppling to the ground when two upper levels of the building and a section of the roof collapsed into a deep excavation pit below.

The incident has left a scar on the side of the three-storey villa and ignited debate over the risks posed to historical buildings amid a residential development surge sweeping Sydney’s suburbs.

The collapse occurred during a $9.9 million redevelopment aimed at transforming the 1890s villa into five ultra-luxury residences.

The project, approved by the Land and Environment Court after a protracted planning battle with Woollahra Council, was promoted as a “sympathetic” development that would retain the original villa while adding new wings and a multi-level basement.

Michael Kounellis, director of builder Trescon, described the collapse as a “freak accident” which he attributed to suspected “flawed geotechnical advice”.

He said the lower section of the building had been scheduled for removal under the approved plans, but the upper levels were never expected to be affected.

“The upper levels came down without notice,” Kounellis said, adding that the incident had been self-reported and that the company intends to rebuild the damaged sections of the home.

According to a preliminary report from Woollahra Council, an on-site project manager heard “audible structure-borne creaking noises” shortly before the incident.

Cracking was also observed at ground level, indicating potential movement linked to excavation works taking place adjacent to the building.

The report stated that part of the heritage facade and a structural wall gave way shortly after an opening was created beneath the facade wall.

The situation worsened on March 16 when a further partial collapse involving an upper-level wall was reported, resulting in the need to remove an unstable section of the building to prevent additional damage.

Kounellis denies excavation works were responsible for either collapse.

The site has since been the focus of multiple inspections by Woollahra Council, the Building Commission NSW and SafeWork NSW.

On March 13, SafeWork issued an improvement notice requiring Trescon to implement corrective measures, including stabilisation works under the supervision of independent geotechnical and structural engineers. In a statement, the Building Commission said it was working alongside SafeWork to ensure compliance with those directives.

Woollahra councillor Mary-Lou Jarvis described the partial collapse of the property as “devastating”, noting Hillcrest had been a largely intact example of high-end Victorian architecture along the harbour coastline.

“The building has stood the test of time for over 100 years,” she said.

“What we’re seeing now is what can happen when very substantial development and deep excavation [more generally] are introduced into a coastal environment with challenging ground conditions.”

Her comments reflect broader anxiety across Sydney, where a surge in multi-storey redevelopment activity – often involving deep basements and complex engineering works – has coincided with a series of structural incidents.

Since January this year, residents in Botany and Kensington have been forced to evacuate their homes at the direction of NSW Building Commission, after nearby construction work compromised the integrity of their properties.

Developer Positive Investment Enterprise, in a statement, said all required safety and reporting protocols had been followed. The company said its immediate priority was securing the site and preparing for restoration works.

“At all times builders followed proper procedure and methodology in dealing with a heritage building including excavation works,” the statement read.

“We are committed to ensuring that upcoming repairs, with appropriate approvals, will restore the facade to its former glory.”

The collapse marks the latest chapter in a long-running planning saga surrounding Hillcrest. Since 2020, the property has been the subject of multiple development applications and modifications.

Woollahra Council initially rejected redevelopment proposals and secured an interim heritage listing to protect the building before the Land and Environment Court ultimately approved the redevelopment in 2021.

Woollahra Council has said any further work at Hillcrest will require a new development application, including a detailed heritage impact statement, and it retains the authority to order the restoration of the damaged sections of the property.

The development is being marketed for sale online with a listing boasting “five ultra-luxury residences” with sweeping views of Sydney Harbour, the Opera House and the city’s “glittering” skyline.

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