One of Mosman’s most talked-about addresses has found a new owner, with the Spaceship House selling for $6 million — a full million dollars above its asking price — and well before its scheduled auction date. The sale of 2B Mosman Street, known locally as the Spaceship House for the way it appears to hover dramatically above Mosman Bay, has drawn attention not just for its striking result, but for the extraordinary level of buyer interest the one-of-a-kind home attracted.
The property — formally known as the Collins House — had been listed with a $5 million guide and was due to go under the hammer on Friday, 18 September. It sold nine days early.
David Grant of De Brennan Property said interest in the home was strong from the outset, with 112 inspections, 13 contracts issued, and three serious parties ultimately competing for the keys. The buyers are believed to be a Sydney family.
It is not hard to understand why. The three-bedroom home with its distinctive fibreglass facade and showstopper rooftop terrace occupies a position that few properties in Sydney can match, with sweeping views over Mosman Bay and an architectural pedigree that has placed it in magazines and architectural lectures across the country. The Architecture Foundation Australia has recognised it as one of the 30 most important Australian houses of the past 60 years — a distinction that speaks to its rarity as a genuine intersection of architecture, place, and lifestyle.
Grant noted that buyers were drawn from across Sydney by the views and the quality of the renovation, and that while buyer demand is currently strong, low stock levels mean that many are holding out specifically for the right property — when it arrives, competition can be fierce.
The Collins House was built in the late 1970s by architect owners Ian and Roseanne Collins, the parents of Penny Collins, co-founder of the acclaimed Sydney practice Collins and Turner, a multidisciplinary design studio founded in 2002 by Penny Collins and Huw Turner. The home was constructed using dry-jointed, prefabricated fibreglass wall panels and features elliptical windows framing water and bushland views, with underfloor heating and a passive cooling system using ponded water on the concrete roof. The iconic home appeared in Belle magazine as far back as 1978 and has remained a reference point in architectural circles ever since.
The home last changed hands in 2016 for $3.7 million, when it was purchased by Gillian Adams, founder of Gillian Adams Salon, Spa and Dining. The decade since has seen the property undergo the high-end renovation that Grant says proved so compelling to buyers.
The $6 million result represents a striking turnaround for a suburb where quality stock remains tightly held — and a fitting chapter in the story of a house that has, for nearly five decades, refused to go unnoticed.
Published 11-September-2026
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