Short answer. Yes, within limits. The owner may put up works, make improvements the property can take, and plant on rural land — provided the work does not reduce the value of the usufruct or prejudice the usufructuary's right. The condition is not decorative; it is what makes the building lawful.
What the law says
The owner may construct any works and make any improvements of which the immovable in usufruct is susceptible, or make new plantings thereon if it be rural, provided that such acts do not cause a diminution in the value of the usufruct or prejudice the right of the usufructuary.
Civil Code, Article 595 — The Owner May Build and Improve. Read the full provision →
What the owner keeps while the usufruct runs
A usufruct splits the property in two. The usufructuary takes the use and the fruits — the harvest, the rent, the enjoyment. The owner keeps what is left, which is called naked ownership: the title, the right to sell or mortgage his interest, and the right to deal with the thing so long as he does not disturb the other half. This article is one expression of that. The owner has not become a stranger to his own land. He can build, improve and plant on it, because those acts belong to ownership, and the usufruct was never meant to freeze the property in the condition it was in on the day it began.
The two-part limit that governs everything
The permission is conditional in two ways. The work must be something the property is susceptible of — improvements the immovable can actually take, and new plantings only if the land is rural. And the acts must not cause a diminution in the value of the usufruct or prejudice the usufructuary's right. Notice that both branches are tested against the usufruct, not against the owner's convenience or the property's long-term worth. A structure that raises the market value of the land while blocking the access, light or productive area the usufructuary depends on still fails the test, because the harm is measured by what the usufructuary loses.
Where the friction usually arises
Disputes rarely concern an obviously destructive project. They concern construction that occupies part of a planted area, work that takes months and disrupts a tenant, a new building that changes access to the road, or plantings that shade an existing crop. The temporary nature of the disturbance does not automatically make it permissible — a season lost is a fruit lost, and the usufructuary's right is to the fruits. Equally, the usufructuary cannot object simply because he dislikes the change or would prefer the land left alone. He must be able to point to a real reduction in what the usufruct yields him or in the enjoyment he was entitled to.
Practical handling
Deal with it before the concrete is poured. Record the condition of the property, its yield and its access at the start of the usufruct — that baseline is what any later argument about diminution will be measured against. An owner planning substantial work should give notice, set out the footprint and duration in writing, and consider agreeing compensation for any interruption; a written arrangement is far cheaper than a stoppage midway. A usufructuary who objects should object promptly and in writing, stating specifically what will be lost, since silence during construction weakens the complaint afterwards. Where the usufruct arose from a will or a deed, read that document first — it may carry its own terms.