Akaroa Museum in Banks Peninsula is closed because engineers deem it to be earthquake-prone.
The museum's three galleries range from 7% to 32% of the new building standard and Christchurch City Council has decided that anything below 34% will be closed.
Engineers will continue to assess the building over the next two months to determine its capacity to withstand future earthquakes.
Repair and strengthening options will then be considered.
Meanwhile, Canterbury Museum remains closed while its structure is thoroughly investigated.