Sign of the Takahe, Kiwi severely damaged
The Sign of the Takahe and Sign of the Kiwi will require strengthening and repair work before they can reopen to the public.
New detailed engineering reports for both heritage buildings reveal they were earthquake-damaged and would need significant repairs and strengthening to meet even one-third of the new building standard.
Engineers concluded that the Sign of the Takahe, a popular restaurant and bar before the quakes, had a seismic strength of just 15 per cent of the building code.
Damage to the landmark included cracking to stone masonry walls throughout, as well as the loss of several stones from the northwest chimney and arches.
The report said strengthening work was required to bring the building up to the minimum of 67 per cent of the building code.
Options to strengthen the building included the use of steel framing or base isolation.
The report said base isolation could reduce the level of strengthening required to the rest of the building and had the potential to be more cost-effective.
The building, owned by the city council, is listed as a heritage building in the city plan and the Historic Places Trust register.
"Therefore, repair and strengthening works will be subject to resource consent requirements," the report said.
SIGN OF THE KIWI
A detailed engineering evaluation on the Sign of the Kiwi has confirmed it is quake-prone.
An initial evaluation of the popular Port Hills cafe estimated its seismic strength was just 9.5 per cent of the building code.
Damage to the fenced-off cafe included cracking to stone masonry walls throughout, and partial loss of the east window stone lintel.
The collapse of stone masonry walls and stone columns supporting the entrance foyer roof were identified as "critical structural weaknesses".
The report warned: "Failure of these structural hazards could result in collapse of the roof structure, posing a hazard to occupants and persons outside and immediately adjacent or down-slope from the building.
"As the building is considered earthquake-prone, strengthening to at least 33 per cent, with a target level of 67 per cent of the NBS, will be required."
Strengthening options include steel portal frames, plywood wall and ceiling diaphragms, or deconstructing stone walls and reconstructing as a stone masonry veneer on timber framing.
The building is listed as a category 2 heritage building in the city plan and as a category 1 heritage building in the Historic Places Trust register.
City council community services general manager Michael Aitken said the two buildings were among 30 facilities considered a priority for further investigations, funding, and where possible, repairs under its Facilities Rebuild Plan project.
"Engineering assessments on both buildings are at an advanced stage and potential repair options are being considered. Both are important heritage buildings and are not being considered for demolition.
"A recommendation will be made about the future of the buildings to elected members, who will make a decision about how to proceed.
"An opening date for both facilities will be determined once a decision about their future is made. However, it is clear that any repair and strengthening work needed will be significant and is likely to take some time."