'You can't build something on thin air': the Sydney waterfront mansion built 'D-Day style'

By any standard it is one of Sydney’s more ambitious projects. A multimillion-dollar mansion to be built on wildly steep bushland, tucked between its neighbours, perched above the water with only a thin staircase granting access to the road, 30 metres above.

The dream of 67 Seaforth Crescent has brought in many owners over many years. But it is only over the past 19 months that some kind of reality has been built. Dozens of workers have been employed to traipse up and down its steps in service of its potential.

When it is finished, it will have an unspoilt view of the harbour, the waves lapping at its deck, and multiple storeys of luxury living. But in the process lies the problem.

A court ruling means construction is currently frozen, after the council alleged that it had changed from its own development application, is encroaching on other land, and has “unauthorised” extra balconies and stairs.

Around it, the shores of Sydney’s Middle Harbour – separating the affluent north shore from the slightly less affluent northern beaches – are packed with houses. They sit in various states of McMansion, luxury elegance, and neat eco-cottage that nevertheless clearly cost a bomb.

This house, at the foot of the sought-after Seaforth Bluff, is clearly different.

Viewed from the harbour, on a clear Wednesday morning, the house looks like an open face sandwich still being made. It’s just three concrete slab floors with nothing yet in between. Next to its neighbours, gleaming and full-windowed, it looks like a mouth with the teeth kicked out.

It is empty, as it should be. A small yellow buoy line is in the water, guarding nothing. A seagull flies across looking for something to eat.

The first line of the court judgment reads like the opening to a novel. “On a steep battle-axe site on the harbour foreshore at 67 Seaforth Crescent, Seaforth, construction has commenced of a new two-storey detached dwelling with a double car hardstand parking area and an inclinator.”

One neighbour, who lives directly above the house, tells Guardian Australia that it has been a saga. He has a relaxed attitude, and says that the construction has not been particularly annoying, but can nevertheless lay out every twist and turn.

“As you can see, access is awful,” he says, pointing. “The stairs, they are narrow, they are very slippery when it’s wet.”

The difficulty makes every step sound like a wartime manoeuvre. “They brought in heavy machinery from the water,” he says. But there is no marina or jetty yet. When asked how the equipment came in, he replies: “You can sort of dock a boat D-Day style.

“They sort of did this, like on Normandy. You can’t really access it with any dignity on foot, or walk on foot.”

He points again at the stairs. “That’s why no one touched it. It’s like the 1920s, you actually have to hire people to manually carry everything.”

As all the ads in the real estate listings say, 67 Seaforth Crescent is one of the last undeveloped, vacant patches of “absolute deep waterfront land” in a highly sought-after place. It is Seaforth Bluff’s final frontier.

“Previously it was whole bushland, you’d see wallabies hopping around sometimes,” the neighbour says.

The lot had been vacant for years, passed from one person to another, as the neighbours watched with a careful eye.

Development approval was first granted in October 2007, so long ago that the Manly council that ticked it off has since been folded and amalgamated. The site changed hands, and the current owner finally dug in last year. They started work in March 2019. They stopped in February 2020, when the council stepped in.

The owner argued in court that many of the changes were temporary, for the purpose of allowing the construction, and would be removed once everything was finished.

For the upstairs neighbour, the work took place quite literally under his nose. It was the other neighbours who first spotted what was going on. “We can’t really see much from here,” he says. “The house wasn’t really fully in shape until January this year. So we didn’t really know actually.”

But he is relaxed about it. The issue is not the house itself, or the construction, which he says he can’t really hear and is not that annoying anyway. It’s just the process.

For the owner, the process has been long, troublesome and costly. As he explains, every sentence is burdened by the difficulty of the land he chose to build on. “It’s a landslip site,” he says. “It is not full rock.”

Compared to the houses around him, it is easily “about 10 times more difficult”.

As he argued in court, he says that what looks like extra storeys or balconies are just temporary structures that will eventually be filled in.

“You can’t carry bricks and concrete down, it’s like 50 steps going down,” he says. “For occupational health and safety we can’t carry blocks down. We’ve built the structure in such a way that the openings are all there, then those openings will be in-filled with lightweight construction, as per the approved plans.

“From the water it looks like three or four levels, but you can’t build something on thin air. You have to build something below it. The level below is an underhouse which is a non-habitable space. We had to do that for landslip reasons, to tie the building down.”

The owner sighs. “It’s for my family. I am not flogging it off. It’s for my wife and kids, it’s a family home man.”

In the meantime, he will press on. He says some work can start, with additional council approval. He is putting in one of those applications on Monday.

And when it’s done, it will be a dream. “There is no actual dispute – in terms of what the end product is going to be,” he says. “It’s going to be a nice future place for Seaforth.

“It’ll be waterfront, it’ll have a wide open bay windows, and it’s right on the water, it’s going to have a jetty. And deepwater.”

He agrees it is the hardest family home anyone has ever tried to build. But he laughs. “I like the north side.”