Planning rules and natural hazards with a ChatGPT plugin: method
Identify the applicable French PLU, PLUi, carte communale or RNU and the natural hazards of a plot with a ChatGPT plugin, then draft a sourced note.
By Educasium
Install the ChatGPT plugin: Planning rules and natural hazards →
A client calls an architect in Toulouse about extending her house at 12 rue des Lilas (a fictional address, for the exercise). She is certain: "The plot is in zone UB, I saw it on a PLU map I found online." The file she sends is an undated PDF that says nothing about the flooding a neighbour mentioned or about the zoning boundary that seems to cut across the back of the plot. Before sketching anything, three questions need answers: which planning document actually applies, in which version, and which natural hazards affect this specific plot?
This article presents the "Planning rules and natural hazards" ChatGPT plugin made available by Educasium: what it produces, the French regulatory context it organises, how to use it step by step, how it differs from a plain prompt, how to install it in Codex and where its limits lie.
Contents
- What the plugin does and what it produces
- The regulatory context: which document, which version, which hazards
- Using the plugin step by step
- What changes compared with a plain ChatGPT prompt
- Installing the plugin in Codex
- When this plugin is not enough
- Training in AI for architectural projects
- Frequently asked questions
What the plugin does and what it produces
The plugin carries out a preliminary feasibility review. From an address, a cadastral reference or documents, it identifies the applicable planning regime and its version at the date under review, lists zoning constraints and easements, then reviews natural hazards. It delivers a note in French, as TXT by default, or DOCX on request when document tools are available.
Three routes depending on what you have
- Address or plot only: site analysis, regime, constraints and hazards. No building measurement is invented.
- Regulations, dimensioned PDF drawings, sections: comparison with explicit dimensions, keeping the file, page and unit for each value.
- Revit model: read-only, and only if you ask for the comparison and a connector is available. Revit is optional and the plugin provides no IFC reader.
A structured note, not a verdict
The note follows a fixed outline: provisional decision and no more than three priorities, site identity, planning framework with its date and evidence of applicability, a table of checks, a full hazard matrix, input limitations, proposed deliverables (constraints plan, section, clarification requests) and dated sources. Each check gets an explicit status:
| Status | Meaning |
|---|---|
| Confirmed fact | Established by a source, with its scope stated |
| To be checked | Serious lead, evidence still insufficient |
| To be clarified | Conflicting sources or uncertain applicability |
| Not assessed | Check not carried out for lack of data or tools |
| No verified local conclusion | No usable evidence at site level |
"Compliant" and "non-compliant" are reserved for comparisons that are actually demonstrated. Missing data is never labelled as non-compliance.
The regulatory context: which document, which version, which hazards
Identify the regime before reading a rule
In France, a municipality may be covered by a PLU (local land-use plan), a PLUi (its inter-municipal version), a carte communale (a simplified municipal map) or, where there is no document, by the RNU (national planning rules). You have to establish which one applies to the plot. The Géoportail de l’urbanisme, the official French planning portal, gives access to published planning documents and public-interest easements: it is the plugin’s first port of call.
Two traps come up often. An empty response from the Géoportail does not prove the municipality is under the RNU: the status stays "to be clarified". And a published document is not necessarily legally enforceable: file date, approval date and entry-into-force date are distinct, and an amendment or annulment can change everything. When several versions are plausible, the plugin keeps the hypotheses separate rather than picking the most recent file.
The date under review matters as much as the document. A current feasibility study is read against the rules in force; checking an old permit means rebuilding the framework of the time. In our fictional case, the client’s PDF will not be treated as a confirmed rule until its date and applicability are established.
Natural hazards: PPRN, hazard maps and local requirements
Natural hazard prevention plans (PPRN), drawn up by the French State, may cover flooding (PPRI), ground movement, drought or forest fires (PPRIF), and have the force of a public-interest easement. But the planning document may also contain its own requirements, for instance on surface runoff, and hazard maps are often for information only. The Géorisques portal lets you look up this information by address or plot.
The plugin works through a matrix of fourteen hazard families, with no preloaded result for any town: flooding, surface runoff, rising groundwater, clay, landslides, cavities, earthquake, radon, forest fire, coastal flooding, shoreline retreat, avalanche and volcanism, climatic events and heat. Technological risks, if requested, form a separate section.
Using the plugin step by step
- Define the question: scenario (current proposal, alteration, historical permit), use, type of works and project stage.
- Give the location: address or cadastral reference. The plugin points out that an address point does not necessarily cover the whole landholding.
- Attach the documents you have: regulations, drawings, PPR. An image without a reliable scale is never measured.
- Let it identify the regime: type, version, formal acts and evidence of applicability appear at the top of the note.
- Cross-check zones and easements against the plot: if the address point is in UB but the plot touches an N (natural) zone, the boundary is flagged for checking, without assigning N to the whole project.
- Run through the hazard matrix: for each family, result, scope, source, possible impact and action.
- Review the note: date and version of the cited document, each source opened, unread points presented as such.
Sample request, with a fictional address: "Analyse the planning regime and natural hazards for 12 rue des Lilas, 31000 Toulouse. Prepare a feasibility note in French with sources, zoning constraints and remaining checks."
What changes compared with a plain ChatGPT prompt
A one-off prompt often produces a fluent, generic answer: "zone UB, height limited, keep the PPRI in mind". The plugin enforces a discipline.
| Plain prompt | "Planning rules and natural hazards" plugin |
|---|---|
| Often assumes a PLU or PLUi | Identifies the regime and its version at a given date |
| Mixes hazard, requirement and zoning | Separates PPRN, informative hazard maps and planning rules |
| Concludes "no risk" when nothing comes back | An empty response does not prove the absence of risk |
| Rarely cites its sources | Records URL, consultation date and publisher |
| Stays silent about what it did not see | Shows every family, even unresolved ones |
A few safeguards from the method: a runoff class of "0.5 m" does not become a required floor level; a clay class gives no foundation depth; no recorded event nearby does not mean the ground is stable. And the plugin sends nothing to the authorities: it drafts clarification requests, and you decide whether to send them.
Installing the plugin in Codex
The plugin runs in Codex, OpenAI’s agent environment. The download is reserved for participants in Educasium training courses, from the plugin page.
Download the ZIP from the plugin page, then unzip it into a stable folder that will not move. In a terminal, add that folder as a catalogue with codex plugin marketplace add "folder-path", replacing folder-path with the real location. Then install the plugin with codex plugin add archi-risques-fr@educasium-risques-fr and open a new Codex session. The installation file included in the ZIP repeats these commands.
The plugin ships no server or connector: its capabilities depend on the tools in your environment (network, data.gouv connector, PDF reading, Word export).
When this plugin is not enough
The note is a decision aid, not a certificate. It does not replace a certificat d’urbanisme (official planning certificate), the only document issued by the authorities that formally states the rules applying to a plot. Nor is it a geotechnical study, a structural calculation or a compliance certification: a seismic zone or a clay class tells you a specialist must be involved, not what they will conclude.
The review also depends on data access. Without a network connection, the currency of documents is not verified; if a public service is unavailable, the check stays open. Revit is optional, and a height read in a model is neither an NGF elevation (the French official datum) nor a regulatory height until the references are established. Your own review remains essential.
Training in AI for architectural projects
A plugin structures the method; you still need to frame the task, read the note critically and fit it into the project. That is the aim of our Mastering AI for Architecture training, built around concrete practice cases.
Frequently asked questions
Can the plugin replace a certificat d’urbanisme?
No. The note is a preliminary review that organises sources and flags the remaining checks. The certificat d’urbanisme is a formal act issued by the French authorities, which officially states the rules applying to the plot and, in its operational form, can rule on a specific scheme. The note helps you prepare that application and sharpen your questions, but it has no legal standing. Before committing to costly studies, applying for the certificate remains the safest step.
What happens if the Géoportail de l’urbanisme returns nothing?
The plugin does not conclude that the RNU applies. An empty response may come from an unpublished document, a filter applied incorrectly or a temporary outage. The regime is marked "to be clarified" and the note lists the research still to do: the municipality’s or inter-municipal authority’s website, the planning department, other official sources. Hazard and easement checks carry on, because they apply whether or not a PLU exists.
Do I need a Revit model to use the plugin?
No. The main route works without BIM: an address is enough for the site analysis, and dimensioned PDF drawings allow a document comparison. Revit reading only comes into play if you explicitly ask for a comparison with the model and a Revit connector is available, always read-only. No IFC reader is provided: an attached IFC file is only analysed if an extraction tool that is actually available has read it.
How should I check the note before sending it to the client?
Start with the header: identified regime, date under review, document version and the source for its applicability. Open each cited link and compare the consultation date with the date of your meeting. Check that every hazard family appears, including those marked "no verified local conclusion", and that no project value is attributed without its origin. Whatever remains open should stay open in your message to the client.
Once the regime and hazards are clarified, our ChatGPT method for the architectural notice shows how to reuse these sourced elements in the planning application notice.
Funding may be available depending on your eligibility (OPCO, FIF PL). Qualiopi-certified training provider. To build planning and hazard analysis into your practice through our Mastering AI for Architecture training, contact Educasium with your status and your goal. You will find the download and installation tutorial on the dedicated ChatGPT plugin page.