Newcastle's tallest apartment building, tower three at Mirvac's The Royal development opposite Newcastle Beach, is not due for completion until October.

But the uninterrupted outlook across Newcastle Harbour, Stockton and Newcastle Beach from the top floor reveals some of the allure behind its five yet-to-be-completed penthouses and gives reason for their million-dollar price tags.

The most expensive of the 16th-floor penthouses is the only one to be bought so far, sold off the plan in November 2008 for $4.495 million.

It boasts three bedrooms across about 325 square feet, en suites in secondary bedrooms, a triple lock-up garage and 300-degree water views.

The unit's sale smashed Newcastle's previous apartment price record by more than $1 million, set in 2004 when a penthouse in The Azura complex was bought for $3.4 million.

Prices for remaining penthouses start at $2.5 million each and many smaller apartments have been snapped up.

"We have already contracted a number of apartments priced from $285,000 for a studio," Mirvac NSW development chief executive John Carfi said.

"The final apartments in The Royal are exceptional value, including a mix of two- and three-bedroom residences starting from $845,000."

Two smaller buildings in The Royal's $170-million stage one development have been finished ahead of their original completion date of late 2010.

Site manager Scott Blogg said that to be so far ahead of schedule was rare and put it down to a lack of rain and wind, which helped avoid long delays.