The Opera House and the Michael Fowler Centre have been issued with earthquake-prone building notices, but have been deemed safe to remain open.
Wellington City Council says the Opera House is at 15 percent of the level of safety required by new building standards, while the the Michael Fowler Centre is at 20 percent.
The council has seven-and-a-half years to strengthen the buildings.
Wellington City Council chief infrastructure officer Siobhan Procter told Morning Report staff must now assess how to fix them.
"It is disappointing, but it's not unexpected. We do have a number of earthquake prone buildings - over 580 in the city in total - and so it's not unexpected that some of those are council owned."
She said work on the two buildings was expected to start within the next three to five years when "the probability of a significant earthquake happening in that period is very low".
The Opera House is a 100-year-old venue that holds almost 1400 people.
Michael Fowler Centre has a two-level auditorium that holds up to 1800 delegates.