Blackburne’s controversial Ocean Grand development in City Beach, which is to launch this weekend, is shaping up as the highest-value apartment project ever undertaken in WA.

Total sales are expected to reach about $720 million — almost double the apartment value of Blackburne’s $350m One Subiaco development and its $400m Grove project.

It is also well ahead of the next most expensive apartment development, South Perth’s $450m Civic Heart complex.

Developer Paul Blackburne said 57 apartments, valued at $200m, had already been sold ahead of this weekend’s official launch.

In a clear sign of the depth of wealth in the downsizing baby-boomer market — the primary demographic for luxury apartments in Perth’s western suburbs — the average apartment price is about $3m.

“This is the strongest market for ultra-luxury apartments we have ever seen,” Mr Blackburne said. “There is so little supply and increasing demand from baby boomers whose homes have doubled in value — from $2m to $4m, or $5m to $10m — in just five years.

“That is really driving demand for much larger, high-end apartments in the $2m to $10m range, which is most of what we are selling.

“When you’re selling more than $200m worth of apartments before the public launch, it tells you there is real depth of demand for this type of product.”

Newly released images reveal a refined vision for the complex, which has recently undergone several design changes.

Mr Blackburne said the revisions included reducing the size of the tavern from 1000sqm to 400sqm.

The changes prompted a strong response from the Town of Cambridge, which has long opposed the controversial apartment tower.

Mayor Gary Mack complained that the 25 per cent reduction in commercial space — from 6408sqm to 4752sqm — could undermine employment, services and amenity that had been promoted as public benefits.

“While there are improvements in design, accessibility, parking and landscaping, there remains a further loss of commercial activity, which weakens the intended mixed-use role of the site,” Mr Mack said.

Mr Blackburne declined to respond directly to the mayor’s comments but said the ground-level area would still be double the size of the former Ocean Village shopping centre.

“There was recently an improvement to the ground-level plans based on feedback from bar and restaurant operators,” he said.

“It is important to note that a licensed venue is still proposed, offering quality food and a wine-bar experience. There is exactly the same number of food and beverage offerings as in the previous plans.

“Under the local planning strategy, the council sought a 48 per cent increase in ground-level floor space. What we are proposing is more than double that — a 104 per cent increase in retail area.”

The project also marks a clear strategic shift for Blackburne into the $3m to $10m apartment bracket.

Resident-only facilities include a pool, cabanas, alfresco dining areas with barbecues and a pizza oven, private dining rooms and lounges, health facilities including a cold plunge, sauna, steam room and spa, a golf simulator and concierge services.

Public amenities will include a retail precinct featuring a boutique supermarket, restaurants, cafes and a wine bar, along with health and medical services, retail outlets and a new playground.

“People often forget that developments like this also free up more than 200 large homes in the area,” Mr Blackburne said.