Housing and property · Soil · studies and transmission
French geotechnical surveys: G1, G2 and responsibility
A prior land study and a project-specific study serve different stages. Within the clay shrink-swell regime, the seller supplies the prior study for attachment, then the client transmits relevant documents to builders. Check parcel, date, permitted use and project content. Statutory alternatives prevent saying G2 is invariably compulsory for every sale or construction project.
- Official texts cited
- Sources checked on
- Drafted with AI assistance, our method
General legal information with official references and dated checks. It is not personalised advice: for a decision that commits you, have your situation checked by a qualified professional.
Julie by AlphaDeep
Does a risk statement replace the study?
Your land seller or builder mentions G1/G2: let’s identify the stage and documents already transmitted.
3 free questions at signup. Avoid names and sensitive information.
When does the seller supply the prior study?
For qualifying undeveloped buildable land in the exposed zone, the seller supplies the study attached to the promise or otherwise deed. Sectors not permitting individual houses are excluded by the statute.
Related step: Housing and property
Code de la construction et de l’habitation, article L132-4Code de la construction et de l’habitation, article L132-5
What does the governing text say about studies and transmission?
En cas de vente d'un terrain non bâti constructible, une étude géotechnique préalable est fournie par le vendeur.
Cette étude est annexée à la promesse de vente ou, à défaut de promesse, à l'acte authentique de vente.
In plain English: For qualifying undeveloped buildable land in the exposed zone, the seller supplies the study attached to the promise or otherwise deed. Sectors not permitting individual houses are excluded by the statute.
What needs checking on the map from July 2026?
The ministry identifies revised mapping for specified transactions concluded from 1 July 2026. Keep parcel and applicable version: an old screenshot or national percentage does not classify your land.
Related step: Property diagnostics for a sale in France: which ones for your home, and how long they stay valid
What does the client transmit before building?
For the specified residential or mixed buildings with at most two dwellings, the prior study is transmitted to statutory builders. If absent from title, the statute provides an equivalent prior or project-specific study.
Related step: Check a project against a French planning certificate
Who supplies which document at each stage?
Fictional example: land sold in October 2026, study unknown; the dossier requests applicable mapping and attachment before concluding.
Fictional example · Your preparation worksheet
The worksheet assigns documents to check by stage. It neither designs foundations nor certifies that G2 is always compulsory.
| Item to check | Value or document |
|---|---|
| Mapping to check | Revised 1 July 2026 mapping, depending on transaction |
| Document chain | Parcel → study → attachment → transmission to builder |
Identify parcel, mapping applicable on the contract date and permitted use.
At sale, check the seller’s prior study and attachment to promise or deed.
At construction, check transmission, relevant study and technical solution under L132-6 and L132-7.
Scope depends on zone, land, use and project. G1/G2 study missions are not a two-choice legal verdict.
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Which documents belong together?
| Point | Check |
|---|---|
| Sale | Land, zone and prior study |
| Construction | Project and transmission |
| Technical | Check recommendations or regulatory solution |
Code de la construction et de l’habitation, article L132-4Code de la construction et de l’habitation, article L132-5
Is G2 always compulsory?
No universal formula establishes that. L132-7 combines study recommendations and regulatory techniques under its conditions. Separate the technical mission name, identified risk and legal duty for the particular operation.
Related step: French CCMI acceptance: record defects
Code de la construction et de l’habitation, article L132-6Code de la construction et de l’habitation, article L132-7
How should documents be organised before signature?
Organise mapping, land title, full study, attachments, plans and transmission evidence. Ask the professional to explain the chosen solution. Organisation replaces neither geotechnical analysis nor foundation design.
Code de la construction et de l’habitation, article L132-5Code de la construction et de l’habitation, article L132-7
What else should you know about studies and transmission?
Does a risk statement replace the study?
No. Identify each document and its own purpose.
Does G1 answer every project-design question?
No. A prior study does not equal every building-specific analysis.
Can the duty be inferred from the town alone?
Check parcel, map, date and statutory project scope.
Does the worksheet certify buildability?
No. It organises documents without granting permission or a technical opinion.
Code de la construction et de l’habitation, article L132-5Code de la construction et de l’habitation, article L132-7
Which sources explain studies and transmission?
- Code de la construction et de l’habitation, article L132-4Légifrance / DILA
- Code de la construction et de l’habitation, article L132-5Légifrance / DILA
- Code de la construction et de l’habitation, article L132-6Légifrance / DILA
- Code de la construction et de l’habitation, article L132-7Légifrance / DILA
- Retrait-gonflement des argiles dans la constructionMinistère chargé de la construction
Texts cited last checked: 20 October 2026