The potentially lucrative listing of St Andrew's Cathedral as a heritage icon may hamper future gospel work, say staff.

Sydney's St Andrew's Cathedral, along with four other places of worship, has been listed on the NSW Heritage Register, recognising its status as one of the city's landmark buildings.

The inclusion on the register opens the way for the Cathedral property trust to apply for state government funds to maintain the aging edifice.

Chairman of the trust, Robert Tong, says the state government has already provided $2 million dollars towards the Cathedral's recent refit.

"Now we’re listed we’ll be regularly filling in the forms for more assistance," Mr Tong says.

But clergy and members of the cathedral chapter are more cautious about the development.

Dean of Sydney, Phillip Jensen, says he agrees with the desire to retain buildings of historical significance, but he is concerned about the level of preservation.

The Heritage Register listing prevents any changes to the interior or exterior of the cathedral without the prior permission of the Heritage Council.

Mr Jensen points to a wall that has been left half-painted because the unfinished task pre-dates the building's preservation order.

"Buildings are built for people, and no building has ever been static. This cathedral has been adapted many times for the sake of ministry. I would not like to see it fixed at any point be it 2004 or 1874," Dean Jensen says.

However Mr Tong believes the Heritage Council will take a lenient approach to matters of day-to-day maintenance.

"The Heritage Register understands that the interior of the church building, because of changing expectations of congregations, is not fixed in the 1850’s. They have an understanding that these things develop according to needs and so I understand they are going to be reasonably receptive to the need to change things," he says.

But Mr Neil Cameron, a member of the Cathedral's chapter, believes difficulties will arise when the congregation decides to adapt the building to meet changing ministry needs.

"It’s common these days for a screen for a projector to be installed in a church - but if the screen involves attaching anything to any part of the building it can only be done with the consent of the heritage council," Mr Cameron says.

He points out that the refurbishment of valuable space in the cathedral's chapter house is now hanging on Heritage Council approval.

"The conservation order also extends to the chapter house, parts of which are unsafe due to white ant damage."

Dean Jensen says he hopes that the cathedral's listing will help to expedite renovations rather than bury them in applications.

"Heritage listings sometimes lead to silly and nit-picking preservation. Preservation needs to be in keeping with the purpose of the building," he says.

Dean Jensen hopes the government will counterbalance the limitations imposed by the listing with sufficient funds to carry out the work.

"Nothing in this building is standard, so every time you do something you have to have it specially made," he notes.

The treatment of the cathedral is likely to prove a test-case for the diocese, with more than sixty Anglican churches likely to be considered for heritage listing.

Mr Cameron says few are ready for the load listing would entail.

"Most of them are in the older parts of Sydney and are those less likely to be able to support the financial burden. And even those with resources are faced with significant costs," Mr Cameron says.