Conquest's 150-home Castlecrag towers move to assessment stage

A NSW Planning Portal check on 1 November 2026 shows Conquest’s proposed twin towers at 100 Edinburgh Road, Castlecrag, in Sydney, have moved into the assessment phase of the state significant development process, after a public exhibition drew 1,299 submissions. The application, SSD-90134958, proposes a development of up to 13 storeys, with two residential towers on a four-storey podium holding 150 apartments including 10 affordable homes, on a 5,099 sqm site in the Willoughby City local government area. The portal lists the proposal as an HDA Housing development type.

Why it matters

The scheme would redevelop a corner site that once held the Quadrangle neighbourhood shopping centre, demolished in mid-2025, adding lower ground and ground floor retail, five basement parking levels, services and rooftop communal open space. Conquest, the developer behind the proposal operating as Edinburgh Group Developments, bought the DA-approved site from Dr Stanley Quek’s Greencliff for $69 million in May 2025, according to a report by The Urban Developer. That earlier approval, granted in December 2024 by the Sydney North Planning Panel, covered a smaller building of 38 apartments with a supermarket. Conquest’s current proposal scales that up to 150 apartments across two towers, with unit typologies ranging from one to three bedrooms plus duplexes and penthouses, and retail planned to include a supermarket, restaurants, cafes and potentially medical offices. The site sits about 8km north of the Sydney central business district and 2.5km from Artarmon station.

The numbers

The planning portal’s record shows 1,299 submissions were made on the application during its public exhibition, with the portal listing 17 Response to Submissions documents alongside 43 environmental impact statement attachments and seven agency advice documents. The Urban Developer reported in April 2026 that Conquest’s upsized proposal carried an estimated development cost of $106 million, although Conquest had floated a total cost of $250 million for the smaller 38-apartment version; those cost figures come from the outlet’s reporting rather than the planning record, which does not list a project cost. The same report named FJC Studio as the scheme’s designer.

What’s next

The application now sits with the assessing agency, the stage that precedes a recommendation and determination under the state significant development pathway. The portal also lists five additional information documents on the file. The volume of response, almost 1,300 submissions on a scheme more than triple the size of what was previously approved on the same corner, sets up a test of how the state significant pathway handles a late uplift pursued under the Housing Delivery Authority.