renovigi

Four pieces, all of them ones you already have. Re- again, nova new, -ig- to make, -i the infinitive. To make new again. English needs renovate for a building, renew for a contract and do up for a kitchen, and Esperanto spends one word on all three because the underlying idea is identical.

The igi and iĝi pair, on a word that shows it clearly. Renovigi is transitive: you renew something. Renoviĝi is what happens to the thing: la kontrakto renoviĝis, the contract was renewed, with nobody named as the renewer. The same split runs through the whole language, which is why plibonigi is to improve something and pliboniĝi is to get better, and why mortigi is to kill while morti is to die. Learn the pair here on a concrete verb and the abstract rule stops being a rule.

The fence with the repair words. Ripari is to repair: something is broken, and you put it back the way it was. Renovigi does not require anything to be broken; a perfectly sound Victorian house can be renovigita, and so can a passport. Restaŭri is to restore, which means returning a thing to a former state rather than making it new, and it is the word for a painting or a monument. Konstrui is to build from nothing.

The rest of the family. Renovigo is a single act of renewal, renovigado the ongoing work, renoviga the adjective, renovigebla renewable, as in renovigebla energio. Novigi without the re- also exists and means to innovate, which is a nicely honest way of putting it.