The sentence that has a shift in its verb voice is:
"The building was built in 72 AD, but it was not built in one day."
In this sentence, the first part ("The building was built in 72 AD") uses the passive voice, while the second part ("it was not built in one day") remains in passive voice as well. However, because they are conjoined, the structure suggests a shift in focus even though they maintain the same passive voice.
The other sentences maintain a more consistent structure without a noticeable shift in voice.