By ANNA USHER

A nine-storey apartment tower planned for Muston St would be one of the tallest in Mosman’s mega-lot building boom, in an $81 million development the local council is powerless to stop.

Four homes on Muston St, a few hundred metres east of Mosman village, are set to be bulldozed for 38 apartments, three years after the 1,831sqm site was quietly bundled up and sold to developers.

The state’s planning department issued its assessment requirements for the project on Tuesday, the first formal step toward a build under the NSW Low and Mid-Rise Housing Policy.

Mosman Collective understands the tower would rise to 29.8 metres over two levels of basement parking, and house around 120 new residents.

The mix would be 16 two-bedroom, 20 three-bedroom and two four-bedroom apartments, totalling about 5,232sqm of floor space.

The plans set aside 28 per cent of the site as communal open space.

Because the build is costed at more than $81 million – above the $75 million threshold – the project is classed as State Significant Development. That means it will be decided by the NSW Minister for Planning, not Mosman Council.

It is a scenario Mosman Mayor Ann Marie Kimber knows well. She has said there is “very little” the council can do when a development complies with the new state laws.

Speaking about the wider wave of mega lots, Cr Kimber previously told ABC’s 7:30 Report the reforms would “change the whole landscape of Mosman and all the suburbs around Sydney”.

Sold with an 8.5-metre limit

When the four homes were marketed together in 2022 they were spruiked as a “Mosman Village development site” with water views to Sydney Heads – and an 8.5-metre height limit on the R3-zoned land, or about two storeys.

The new housing reforms have since lifted the base height on the site to 22 metres.

By handing over 15 per cent of the floor space as affordable housing, the developer unlocks a 30 per cent bonus, pushing the cap to 28.6 metres. The plans go higher again, to 29.8 metres, with a request to break past even that.

But the affordable housing buying all that extra height is modest.

Information obtained by Mosman Collective reveals just five of the 38 apartments would be set aside as affordable – and only for 15 years, after which they can be sold or rented at full market price.

Who’s behind it

The site is being developed by Prosper, a “new generation builder developer” owned by construction group Growthbuilt. The plans were drawn up by Keylan Consulting, with Plus Studio as architect.

None of the four homes are heritage listed. The blocks stitched together to form the super site span more than 1,800sqm:

• 58 Muston St: 563sqm
• 60 Muston St: 329sqm
• 62 Muston St: 310sqm
• 64 Muston St: 612sqm

What the neighbours fear

The proposal is yet to face the public, but it is exactly the kind of development that has lit a fuse elsewhere in the suburb.

When a similar mega-lot tower was lodged on nearby Bond St, more than 50 residents objected, fearing lost views, less sunlight and the end of their street’s village feel.

The developer wants cars coming and going from Muston St, at the south-eastern corner of the site, and garbage trucks using Post Office Lane at the rear. The access plan is still to be reviewed by a traffic engineer.

The developer will also have to weigh the tower’s impact on its neighbours’ views against the Land and Environment Court’s “Tenacity” principles, the planning benchmark for harbour-view disputes.

The wave rolls on

Planning documents reveal “several” more sites near Muston St are already in the pipeline, all leaning on the same state rules.

Prosper plans to lodge its full application late this year. Residents will get their say once an environmental impact statement goes on public exhibition.

If approved, construction could start in late 2027.

Mosman Collective will follow this one every step of the way.