The Chapelli's building was built by landowner John Broeren in 1995, and was originally home to Burlings Restaurant and Bar.
The property was occupied by Wellington restaurateur Steve Chapman in 2004, who opened the woodfire pizza joint Chapelli's -- which Mrs Kunz said was "extremely successful".
The restaurant was later taken over by new tenants, who re-named it Cindyz, but customer numbers dwindled and the tenants vacated in 2010.
These days, the building is a shadow of its former self -- with windows either "full of cobwebs", boarded up or broken, graffiti covering the exterior, and rude words scrawled in the dust around the front door.
"I'd walk past it every morning, and it was quite upsetting," Mrs Kunz said.
"It's not a good look -- that kind of thing does drag the town down."
But it was a strongly-worded description of the building in one of food critic David Burton's reviews which galvanised her into action.
"That was the catalyst -- it hurts when people make these kind of comments."
Last Thursday morning, Mrs Kunz and a small group of volunteers got to work in the courtyard, pulling weeds, washing windows, sweeping debris and pruning trees. Their work was finished within about three hours.
"You should have seen it before -- you could barely see the cobblestones underneath," volunteer Mary Mason said.
Mrs Kunz said she hoped the property would eventually be leased.
"It's a lovely space -- it's a business begging to get going again."
Mr Broeren, who turned up to lend a hand, said he was grateful for the volunteers' help.
"When you see graffiti everywhere, you do wonder about our community," he said.
"But this restores your faith in human nature."