Australia's Anglican Diocese of Newcastle will consult with parishes beginning in January to develop a 15-year master plan, the diocese's administrator said after a confidential draft report was leaked indicating consultants' proposal to sell off more than half the diocese's church buildings.

Bishop Peter Stuart, the administrator of the diocese, told The Newcastle Herald that the review of parishes in the Newcastle and Newcastle West Deaneries began months ago. Newcastle is the second most populated area in the nation's state of New South Wales.

"It [the report] does not represent the views of the Diocese but contains preliminary data which will be the subject of consultation in parishes beginning in January," he told The Herald.

"A report on the review will be presented to the Diocesan Council sometime in 2013. At that time the council will consider what action to take."

Bishop Stuart that the report - created by consultants NBRS Partners - was part of a review that began with full knowledge that the current Bishop of Newcastle, Dr. Brian Farrawn, would be retiring.

He said he was "disappointed" that the confidential document had been leaked to The Herald.

The confidential draft report states that the Diocese could make nine of its 15 Newcastle and Newcastle West churches "redundant" as part of a future growth strategy, the report states.

The report states that problems facing the diocese include falling congregation numbers, maintenance problems, lack of financial contributions, no on-site parking, fire risk issues and disconnect with the community.

The report states that many of the Diocese's buildings have "strong character," are in prime locations and warrant investment to improve relevance to young families.

''The opportunity for the Deaneries lies in a consolidation of the wealth of resources to help tap into the emerging young professional class of families and couples," the report states.

The report states rankings of churches by tiers could be used to determine staffing levels and investment to boost attendance rates.

Tier-one churches have congregations with more than 450 people and can sustain a ministry and administration team. Tier-two churches have congregations with more than 250 people with two full-time staff. Tier three churches have more than 150 members and one staff member.

"Churches falling below these benchmarks may not be sustainable in the longer term," the report states.