The report applied to both the original part of the building built in 1957 and the extension built in 1992.
The library moved to its present War Memorial Library site in 1959 and became subscription-free for borrowing general books in the 1960s.
The low seismic rating indicates uncertainty in how the building would respond in the case of an earthquake.
Hastings District Council said a seismic risk evaluation report prepared by Kestrel Group as a result of the rating said the building could be occupied while plans are developed and implemented and therefore will remain open.
As with other earthquake-prone buildings, the council has 15 years to undertake work to get it up to the code standard.
Group manager of community wellbeing and services Rebekah Dinwoodie said the council had taken the advice of experts when considering the immediate future and public use of the library.
“The building is not considered to be at any imminent risk of failure in a moderate earthquake. The likelihood of an earthquake large enough to cause structural failure in any given year, or over a five to 10-year period, is considered low.”
The council also has alternative library services such as the Flaxmere and Havelock North libraries or the eLibrary available via the Hastings District Libraries website.
The library building includes several elements that many consider to be taonga.
Late last year, efforts were made to repair and restore the famous war mural in the Hall of Memories.
The treatment included cleaning the overall paint surface, along with retouching and repairs to areas where it had lost some colour.
The mural was designed and painted by war artist Peter McIntyre OBE in 1959 and is listed as a public artwork. The mural depicts an assault by the joint branches of the armed forces on an unspecified beach.
Hastings Mayor Sandra Hazlehurst said the conservation treatment had been scheduled regularly to ensure the integrity and long-term preservation of what was an irreplaceable public work.
