Short answer. No. Article 698 is a single sentence and it admits no exceptions: lapse of time cannot legalize any nuisance, whether public or private. Twenty years of an unlawful noise gives the person making it twenty years of conduct, not a right to continue it.
What the law says
Lapse of time cannot legalize any nuisance, whether public or private.
Civil Code, Article 698 — Nuisance Never Legalized By Time. Read the full provision →
Why prescription has no place here
Rights over property can be acquired by long possession, and that is what makes people assume a long-tolerated nuisance must eventually become lawful. The Code refuses the analogy. A nuisance is a continuing wrong, renewed every day it operates, so there is no single moment from which a period could run. And a right to inflict harm on neighbours is not the kind of thing the law will let anyone accumulate by persistence. The article says any nuisance, whether public or private, leaving nothing for an occupier to argue about.
The harder question is whether it is a nuisance at all
This is where these cases are really decided, and age is relevant to it even though it cannot legalise anything. A workshop that has run in the same way for twenty years in an area that has always had workshops is unlikely to be found unreasonable; the same workshop in a street that has since become residential is a different case. What is being weighed is the character of the locality, the nature and intensity of the interference, the times it occurs and whether it is more than a neighbour should have to put up with — not who arrived first.
Your own delay can still cost you something
The article protects the substance of the claim, not every remedy attached to it. Years of saying nothing make it harder to argue that the interference is serious, invite the answer that you accepted it, and limit what you can realistically recover for a period during which you never complained. So the right reading is that your position is preserved but weakened. A person who has lived with a noise for two decades and now wants it stopped is better placed if the complaint can be tied to a change — new equipment, longer hours, an expansion — than if nothing has altered.
Record the interference before you complain
Keep a dated log over several weeks: times the noise starts and stops, what produces it, how it affects use of your home, with recordings and any sound measurements you can obtain. Note who else is affected, since a shared complaint carries more weight than a solitary one. Then check what permits or clearances the workshop holds and what the local rules allow for the area, because a business operating outside its permitted hours or use is often addressed far faster through the issuing authority than through litigation.