Old buildings all the sudden generate more culture?

[dylanmeditates]

I remember seeing in one of my games that a culture-producing building was listed in the city screen as generating more culture than it should have, I think it was 3 instead of 2 or something like that. And I remember reading about how if a building reaches a certain age, it generates more culture. Is anyone familiar with this mechanic that can explain the length requirements for this additional culture on your building?

 

[Izuul]

I believe all culture buildings produce double culture once they are 1000 years old.

It appears you actually asked this same question 5 years ago!
https://forums.civfanatics.com/threads/why-my-library-says-4-culture.538514/

 

[sampsa]

I believe all culture buildings produce double culture once they are 1000 years old.

All except the academy.

 

[Izuul]

Yeah there are a handful of exceptions.

 

[sampsa]

Yeah there are a handful of exceptions.

Palace. Anything else?

 

[elmurcis]

SH monument instead of handmade monument. (if conquer city that has SH but some old cities would have monument already, they would still get 2x culture or not? )