RESTORATIONS to one of the Rose City's oldest and most sacred buildings could run close to the million dollar mark, as the historic church approaches a significant milestone.

St Mark's Anglican Church has stood strong on the corner of Grafton and Albion Sts for almost 150 years, but shifting foundations and aging wiring has seen it begin to shift and crack.

With the church's 150th anniversary approaching in 2018, St Mark's Reverend Rod Winterton and parishioners are facing a bill to the tune of more than $700,000 to get the heritage-listed building restored.

The Reverend said there were number of costs involved from the get-go including the drawing up of a $15,000 restoration management plan, which meant the work would have to be done in stages.

"Initial figures from one lot of stonemasons in Brisbane is $650-$700,000 for stonework," he said.

"We have a hodge podge of wiring inside the place - we're looking at $20-$25,000 for the rewiring.

"We've got to get the stained glass windows new lead and frames, which could cost $65-$80,000."

Cracks had appeared in some of the sandstone walls, while termites eating away at the floorboards would mean a lot of timber work had to be done.

"The west end of the church is the worst end. We can get that under way when we have $250,000 in the bank," Mr Winterton said.

"We're working on getting it started for the anniversary."

St Mark's Restoration Committee chairwoman Penny Campbell-Wilson said despite the need for restoration work the church was sound and wouldn't be falling down.

"We've done a lot of fundraising ourselves. We're quietly confident we will raise that money from grants, parishioners and the general public," she said.

"We've received some quite handsome donations so far. We're positive we'll get there."

Mrs Campbell-Wilson said the St Mark's Hall also needed an expensive restumping.

While the church is sacred to many religious people in the town, Mr Winterton said it also had a lot of significance in the wider community.

"It's more than an Anglican Church. Along with St Mary's and the Uniting Church it's part of the face of the community," he said.

"Visitors say there's something about the building that heals the soul - it's a touching place."

St Mark's is believed to be one of the oldest churches in Australia.

Donations to the restoration appeal can be made directly to the church.