Renovation is the act of renewing or restoring something. If your kitchen is undergoing a renovation, there’s probably plaster and paint all over the place and you should probably get take-out.
The roots of renovation refer to newness and doing something again — it’s from the Latin re- for "again" and novare which means, "make new.” A rundown building is in need of renovation, or a website that's being redesigned is under renovation. After renovation, things look new and improved. Before the word underwent renovation, in the early 15th century, renovacyoun meant "spiritual rebirth,” which is how you might feel after your kitchen is redone.