Mayor Peter Chin ended weeks of speculation on Monday when he confirmed the council would investigate moving the library to the former chief post office building, after signing a joint venture feasibility agreement with building owner South Canterbury Finance to investigate the building's potential.
Otago Regional Council chairman Stephen Cairns also confirmed moving his council's offices to the building was an option.
Mr Chin said the move could solve space problems at the library, and help rejuvenate an Exchange that has experienced a considerable decline in the past half-century.
The plan is the latest in a list of major multimillion-dollar projects the city council has embarked upon, including the Forsyth Barr Stadium, the Dunedin Centre and Town Hall redevelopment, the Wall Street mall development and the Tahuna sewerage upgrade.
The latest project, though, is at an investigation stage only, and all councillors spoken to agreed putting some thought into the matter was a good idea.
"I think it's well worth having a look at," Cr Chris Staynes said.
But he needed to understand the unique features of the building before deciding whether it was suitable for a library.
Its location, which had "pluses and minuses" had to be considered, and the cost of the move had to be calculated.
Cr Kate Wilson said the cost would not necessarily be more than the $25 million set aside in the council's long-term council community plan, though nobody knew yet what it would be.
"Let's just see what the opportunities are."
Cr John Bezett said the move could be a good one if the ORC and others were on board, though there could be implications for the harbourside development if the ORC did not build its headquarters there.
"As with anything like this, it looks like a good opportunity, so let's pursue it.
"We have to look at the case for the present library, and the proposed library in South Dunedin."
Cr Dave Cull said the feasibility study would show whether the idea was a good one or not.
Other councillors spoken to agreed investigating the option made sense, and rejuvenating the Exchange was important.
Only Cr Paul Hudson refused to comment on the issue, because, he said, the council had not discussed it, and he had not talked to library management about it.
