The three regimes
| Regime | What it requires |
|---|---|
| Building permit | a complete file, processing and a decision |
| Notification of works | written prior information to the mayor |
| Exemption | no formality |
The principle is the permit. The applicable text covers a very wide range of works, and exemption is the exception.
Notification requires a period before works begin, set by the municipal regulation, meaning it does not authorise an immediate start.
Exemption does not exempt from the substantive rules. Works free of formality remain subject to planning provisions and the building regulation, and non-compliance carries the same sanctions.
The trap of the numerical threshold
This is the most poorly reproduced point, and the error is systematic. An exemption from permit does not exempt from the rules.
An exemption exists for individuals erecting a building for their own use on land they have the enjoyment of, where the cost of the works does not exceed an amount set by law.
That amount is expressed exclusive of tax and at index one hundred, the reference index being the general index linked to consumer prices.
It is therefore not an amount applicable in current euros. The statutory reference value must be converted to the index in force to obtain the threshold actually applicable, which is far above the nominal amount appearing in the text.
Reproducing the nominal amount without conversion makes the exemption appear far narrower than it is, and this is the error most presentations of this regime repeat.
The converted threshold is to be confirmed by the municipality, the conversion depending on the index applicable at the time of the works.
What moves works up a regime
Four situations, to check before concluding that a lighter regime applies. They bring a project back within the permit requirement.
Location in a protected area. Works normally subject to simple notification may there require a full permit.
Affecting load-bearing structures, the façade or the roof, which takes works outside the interior-alteration regime.
Change of use, even without substantial works, since it touches land use.
The presence of an easement or protection on the plot, covered in the article on easements and protections.
Why thresholds vary
A direct consequence of the Luxembourg model. The list of exemptions differs between municipalities.
The issuing procedure is determined by each municipality's building regulation, and may therefore vary.
The lists of works subject to permit or notification sit in that regulation, which is why the same works fall under different regimes depending on the territory.
A model document exists nationally as a template, but its adoption and adaptation fall to each municipality.
Consequence: experience gained in one municipality does not transpose, developed in the article on why the rule is municipal.
The safe method
Three steps, quicker than getting it wrong. They establish which regime applies.
Describe the works envisaged in writing to the competent municipal service.
Ask for written confirmation of the applicable regime, not an oral opinion.
Keep that confirmation, which serves as evidence of good faith in the event of inspection.
What this means for a professional
Four rules.
Never conclude that an exemption applies without municipal confirmation, the error exposing the client to a stop notice.
Never reproduce the numerical threshold without index conversion, nor publish it as it stands.
Check for location in a protected area before any reasoning about the regime.
Recall that exemption from formality is not exemption from compliance.
This article reflects the regulatory framework at the date of checking and serves professional orientation. It does not replace consultation of the municipality or legal advice.