Concerns are mounting that the former Sims Engineering building in Port Chalmers faces ''demolition by stealth'' after being left exposed to the elements.
Specialist contractors working for the Dunedin City Council have spent the last two months removing the asbestos-based roof of the old brick foundry building, parts of which date back more than a century.
The work began in February and was originally expected to take two months, at a cost to the council of $215,606.
The council had planned to install a temporary cover to protect the building.
However, with the roof now off, council recreation planning and facilities manager Jendi Paterson yesterday confirmed the building would be left without any cover through winter.
The delay was because more work needed to be carried out, including the removal of further asbestos materials and a structural assessment of the rest of the building.
That work was expected to begin in spring, depending on contractor availability, and the building would only be made watertight then, she said.
The building's brick and steel materials meant ''the risk of damage by the elements is low'', she said.
That was not good enough for Graeme Wall, who said the council appeared to be ''deliberately trying to ruin the building''.
''It's demolition by stealth,'' he said.
''It's an industrial building and it will take a bit of rain, but if you're going to leave it for the whole winter - if it's your plan to demolish it, well come clean now and let's have the discussion.''
Mr Wall has been vocal in calling for the building to be retained because of its significance to Port Chalmers' maritime history.
Mr Wall was also a member of the Port Chalmers Yacht Club, which previously leased the building, and was among members whose boats were temporarily locked up following the asbestos scare.
