In the prestigious setting of Middle Harbour, this architect-designed residence, originally conceptualised by Ralph Cunningham and later realised by Jon Mitchell, stands as a testament to architectural vision and bold luxury.

A house 15 years in the making, its journey from inception in 1990 to completion in 2005 marks a commitment to both the form and function of waterfront living, integrating modern design principles in a grand way.

A Fellow of the Australian Institute of Architects NSW Chapter, Cunningham is credited as the true visionary responsible for the overall architectural concept. As you stand in awe of the home’s views, scale and connection to the surrounding waterways, it evokes a sense that this is truly a one-off moment, and something that would be impossible to recreate today.

Currently being offered to market with Sydney property group BresicWhitney, selling agent Anna Chen says the home is a showpiece from a different era, allowing some 1100sqm of internals where a build might ordinarily achieve 500sqm, and around 1600sqm of indoor/outdoor space in total.

“I find it so interesting that these harbour-side trophy homes offer the opportunity to experience something that could never be unveiled under current building parameters,” Anna says.

“We’ve had architects and engineers comment that building on these sandstone cliffs would exceed the multi-million price guide, while obtaining approval for a jetty is another rarity in the modern age.”

Stretching out from the shores below, the existing boating facilities can berth two yachts, with the eastern mooring pen accommodating a vessel up to 50 feet.

The home’s architecture reflects a sophisticated interplay between rectilinear forms and curved elements, creating a structure that is both dynamic and refined. The design’s use of curved balconies and projecting windows captures the movement of the water, while large floor-to-ceiling glass panels focus everything towards Middle Harbour. Built of full brick and concrete, the construction rests against a natural backdrop, with privacy maintained through subtle fenestration on the eastern and western facades.

Privacy is a unique hallmark, offering a sense of seclusion often absent in waterfront properties. Unlike many homes along this same stretch, the curved window projections and strategic architectural features ensure unobstructed outlooks without being overlooked. Outdoor terraces, including a 20m infinity pool, offer a seamless indoor/outdoor experience, further enhancing the natural flow.

Set over five levels, the home was designed not just to be admired but to be lived in. The striking curved staircase and sky-lit interiors complement both communal spaces and private retreats. Every bedroom, with an ensuite and water-facing aspect, embraces the ever-changing marine landscape, offering a quiet escape for both family members and guests.

Practicality for an extended household or entertaining at scale is deeply embedded in the home’s DNA. Two fully-equipped kitchens and a wet bar ensure diverse options, while multiple wings cater to a range of activities, from the theatre to the billiard room. With a commercial-sized lift and an inclinator that leads to garden landings, and down to the jetty, movement is effortless from the entrance to the water.

The boat house and adjacent Japanese-inspired gardens, offer further serene retreats amidst the lush, layered landscape.

Set on a deep frontage, the house’s security and privacy is complemented with a four-car garage and electric gates. In a standout feature for a clifftop designs, the driveway offers ample space and the unique functionality of U-turn space.

The location is as exceptional as the home itself, positioned just 1km from Seaforth’s vibrant shopping village, and 450m from the Spit to Manly walk. The proximity to both natural reserves and urban villages captures the desirable lifestyle of the Northern Beaches.

An extraordinary opportunity and one of Sydney’s best harbour-side offerings, it’s a chance to acquire a house in a class off its own, and experience the culmination of that original 15-year journey between dream, and home.

View the listing here: 41 Battle Boulevard, Seaforth