The collapses at the Rattray St site prompted a warning from the Dunedin City Council's chief building control officer, Neil McLeod, who told the Otago Daily Times public safety around Dunedin's old, disused or unoccupied buildings was the responsibility of the buildings' owners.
"There is a clear responsibility [on the part of the owner] to make sure the building is safe, not only for the occupants but for people walking past."
His comments came after two parapets on the 135-year-old Rattray St building fell on to its roof about 8.50am yesterday, causing the roof to collapse inwards on to the second storey.
Mr McLeod said the building's top two levels were vacant, but the ground floor was home to Dunedin institution the Dragon Cafe.
Some of the brickwork fell outwards, leaving a hole in the roof of the Southern Cross-owned Paterson Building next door.
The cafe was not damaged in the first fall, but the second collapse about 5pm sent a section of the building's front parapet - already leaning out into the street after the first collapse - crashing on to the cafe's veranda.
Nobody was injured in either incident, but the second collapse demolished the iron and timber veranda and scattered bricks and masonry on to the street.
It was not known last night if the cafe was damaged in the second incident.
Nearby workers said the first collapse sounded like a "roar of thunder" and left a cloud of dust in the street.
About 20 people living at the Crown Hotel on the other side of the building were evacuated, although the bar reopened later yesterday.
One of the building's owners, Lincoln Darling, of Dunedin, said he was shocked by the damage.
His company, Anchorage Properties Ltd, bought the building between five and eight years ago but had not upgraded the vacant upper floors since then.
"Like all those buildings, it's original," he said.
The building's fate was now in the hands of the engineers and insurers, with a final decision possibly four weeks away, but he hoped it could be saved.
"The main thing is to get it safe so it's not going to collapse or anything... I hope it's reinstated. I believe it will be."
Bevan White, from consulting engineering firm CPG, which is fixing the damaged building for the owners, said the building's bricks and mortar had deteriorated significantly, leading to the collapse.
Demolition crews were working to make the building safe by removing the most unstable parts one brick at a time, to avoid further damage, he said.
Removing the remainder of the street-side parapet and part of a wall that was cracked and unstable was expected to take up to three days.
The section of Rattray St around the building would probably remain closed to traffic until the safety work was completed.
It would be another few weeks before strengthening and assessment work was completed, Mr White said.
Mr McLeod said the building was "not in very good condition", but the council's role was only to ensure public safety.
Once that was done, the final call on the building's future would be made in consultation between the building owner, the council and the New Zealand Historic Places Trust, although the council had the power to order its demolition as a last resort.
"But we're a long way from that yet."
The building's partial collapse followed the collapse of a 150-year-old bluestone retaining wall on to two cars in an alley off Rattray St in 2007.
And in September last year, an old brick wall beside a disused Princes St cinema fell through its roof, closing the business below for a time.
Mr McLeod said the council had no regime to check buildings' structural stability.
Building control officers only inspected buildings if owners wanted to change their use or rebuild them, where the work would have to meet certain safety standards, or if an engineer advised them of safety issues with a building.
He had no idea how many buildings around the city might be in similar condition to the Rattray St building, but it was likely some required strengthening work.
The companies office lists Anchorage Properties Ltd's directors as Mr Darling and Christina Murphy.
NZHPT Otago-Southland area manager Owen Graham said the building was of historic value in terms of its design, its architecture and because it was one of the oldest surviving commercial buildings in Dunedin.
The trust hoped as much of the building would remain intact as possible. chris.morris@odt.co.nz
