What triggers a permit
Four main tests, to be crossed rather than applied in isolation. They determine whether a permit is required.
Alteration of external appearance, the most frequent trigger in renovation, including for limited work.
Alteration of the loadbearing structure, regardless of whether the work is visible.
Change of use, even without works, a case regularly overlooked.
Change in the number of dwelling units, subdivision or amalgamation.
Like-for-like repair may therefore be exempt, while simply changing joinery visible from the public realm may not be.
| Trigger | What it targets | Frequent case in renovation |
|---|---|---|
| External appearance | Any visible modification | Replacing external joinery |
| Load-bearing structure | Any structural intervention | An opening in a load-bearing wall |
| Change of use | The use of the property, even without works | An office converted into a dwelling |
| Number of dwelling units | Division or merger | A building divided into flats |
Why exemptions do not transpose
Planning is a regional competence, with all the usual consequences. The exemption lists differ from one region to another.
Each region publishes its own list of exempt works, with its own tests and thresholds.
Municipalities may add requirements, notably through local regulations or within particular perimeters.
Heritage and protected areas add a further layer, capable of making consent necessary where it would otherwise be exempt.
The practical rule is therefore to check at the exact address of the property, and not to reason by analogy with a neighbouring project. This connects with the guide on building regulations.
The prior question of regularity
A point specific to renovation, and a source of major blockages. It concerns buildings under heritage protection.
Processing an application on an existing property leads the administration to examine that existing.
If earlier works were carried out without consent, the application may founder on that irregularity, even though the project itself raises no difficulty.
This is frequent on older property, having had several owners and several alterations.
Hence the importance of earlier permits in the preliminary file, covered in the article on the preliminary file.
Checking the regularity of the existing before submitting is therefore a step in its own right, not a formality.
What a permit entails beyond consent
Three knock-on effects, often discovered during processing. They bear on the calendar, the cost and the brief.
Mandatory involvement of the architect, for works falling within that requirement, as the guide on contracts and liability explains.
Triggering of specific energy requirements, where the scale of works brings the project within a major renovation regime.
Particular conditions in the consent, notably arising from opinions given during processing, which may alter the project and its cost.
Those three effects have budgetary and programme impact better anticipated than discovered.
Time as a project datum
A practical point connecting with the contractual branch. The contract must provide for a permit refused or made conditional.
Processing an application takes time the client does not control.
That period must appear in the programme, and the contract should provide a triggering event tied to obtaining consent rather than a date, as the article on periods and interruptions explains.
Starting works before consent is obtained exposes the client, even where the outcome appears settled.
What this means for a professional
Four rules.
Check the regional exemption list, at the exact address of the property.
Verify the regularity of the existing before submitting, that question being capable of blocking an otherwise simple application.
Anticipate the knock-on effects of consent, architect, energy requirements and particular conditions.
Treat processing time as a contractual datum, not as administrative uncertainty.
This article reflects the position of the rules at the date of checking and serves professional orientation. It does not replace technical advice or consultation of the competent administrations.