Changes to the Building Act last year defined an earthquake-prone building as one that is less than 34 per cent of the strength required of a new building - the NCC assessment found Napier Library to be at just 15 per cent as its lowest point.
The 78 IRD staff had worked from home until November, when they moved into two temporary offices in Bower St, and Tennyson St.
At present, the public are advised the best way to contact IRD from Napier is through the IRD customer service call centre.
Meanwhile NCC's Love Your Library campaign, designed to consult the public on future options for a library, has just one month left to run.
At present, Napier City Council provides library services from two locations: a temporary city library within MTG Hawke's Bay, and a branch library in Taradale.
The campaign recently concluded a series of "pop up" sessions across the city to garner ideas from the public but people can still obtain a feedback form online or from any Napier or Taradale library.
"The library building on Station St is still on the table," council chief executive Wayne Jack said.
"All of the council administrative services, including the library, can fit into that building if it's renovated appropriately, and is affordable. So that's still an option, as well as a number of other sites around the CBD that we're investigating too."