Many people assume that if nothing structural is touched, turning a space into something else is not works at all but paperwork. The code treats it differently: it places change of use in the same list as strengthening and extension.
That does not mean every change of use needs a permit. Some cases go through the simplified notification, and the conditions are on the works without a permit page and in do you qualify for notification. Being classified as an intervention decides which rules apply, not automatically that a permit is required.
The list, as it stands
Article 372 paragraph (1) enumerates what counts as an intervention on existing buildings: construction, reconstruction, partial demolition, strengthening, repair, modernisation, modification, extension, rehabilitation, thermal rehabilitation, improvement of energy performance, renovation, major or complex renovation, change of use, protection, restoration, conservation and total demolition.
The same notion is defined again at article 259 paragraph (3), in the chapter on the building permit, with an overlapping list. These are not two regimes; it is the same concept seen from two places in the code.
The eight classes
Paragraph (2) groups interventions into eight categories: maintenance and current repairs; capital repairs; first-urgency intervention; extension; adding storeys; refunctionalisation or change of use; strengthening; and modernisation and rehabilitation.
Each category comes with its own definition, and the definitions are not decorative. They decide which route the works take and, from there, what pieces the file requires.
The rule hidden in “adding storeys”
Letter e) deserves reading word by word. Adding storeys means extending the volume of the existing building by adding further levels, whole or partial, provided the existing building is kept and integrally included. Where that condition is not met, the intervention is treated as partial demolition and reconstruction.
So a project presented as adding a storey, but which in fact dismantles part of what stands, stops being that. It moves onto the demolition route, with the documentation and permitting that go with it. We wrote about demolition followed by new construction in DTAD became PAD.
What this means for your file
Once the works are an intervention, the file is no longer the one for a new building. The detailed survey of the existing building is added, which we covered in the measured survey, and, as the case may be, the technical expert report. The thresholds that call for one, and the incompatibility that comes with it, are in technical expert reports on existing buildings.
And if the intervention changes the brief after the permit is issued, the route is the one in the modification permit.
What to check before commissioning the design
The useful question is not whether you are touching the structure, but which of the eight categories your works fall into. The answer decides whether you need an expert report, a survey, a demolition permit alongside the building permit, or none of them. The basic permitting rules are on the building permit page.
This article is analysis, not legal advice. The provisions cited are from Legea 169/2026, published in Monitorul Oficial no. 661 of 10 August 2026. Check your own situation with the issuing authority.