Becoming a certified property diagnostician in France: the step-by-step route

Property diagnostics is one of the few construction trades in France where competence cannot be self-declared. You do not set up as a diagnostiqueur by buying equipment: the law requires every document of the dossier de diagnostic technique (the technical diagnostic file) to be produced by someone whose competences have been certified by an accredited body. Here is how the route actually unfolds, and where the traps lie.

The starting point: a legal obligation, not a professional standard

Article L. 271-6 of the code de la construction et de l’habitation (construction and housing code) sets the rule: the documents making up the technical diagnostic file — the one the seller or landlord must hand over — are produced by an individual whose competences have been certified by a body accredited in the construction field, or by a company employing certified staff under the same conditions.

Two practical consequences follow.

Certification is personal. It belongs to the professional, not to the firm. A diagnostics company is never itself “certified”: it employs certified diagnosticians. An employee who leaves takes their certification with them.

The certifier is not the State. The architecture has three tiers: the State sets the criteria by arrêté (ministerial order), the Comité français d’accréditation (Cofrac, the French accreditation body) accredits the certification bodies, and those bodies certify individuals. It is the same pattern found in other French schemes — including Qualiopi certification for training providers, except that this one certifies people rather than organisations.

Step 1 — Check the prerequisites before spending a single euro

This is the step candidates skip, and the one that costs the most when handled badly.

The orders in force condition access to the exams on a level of education or on professional experience in the construction field. Those conditions differ by domain and have changed several times in recent years: the order of 24 December 2021 was annulled by the Conseil d’État with effect deferred to 1 September 2024, replaced by the order of 1 July 2024 for asbestos, electricity, gas, lead and termites, while the energy performance survey falls under the order of 20 July 2023.

The habit to acquire: get an accredited certification body to confirm in writing the prerequisites applying to your profile, for your target domains, on today’s date. A training programme found online can be accurate and out of date at the same time.

Step 2 — Mandatory prior training

Turning up straight to the exam is no longer possible: prior training is required before the initial exam, and it is longer for “with mention” certifications (asbestos and lead).

This training is not an open-market course. The so-called arrêtés compétences (“competence” orders) also set requirements applying to the training organisations of diagnosticians: content, trainer competences, resources. A provider that does not meet them cannot deliver this prior training, however well known it may be. Check this before signing — we cover it in our article on the requirements on training providers for diagnosticians.

Step 3 — The two exams

The certification body runs a theory exam, in questionnaire form, then a practical exam placing the candidate in a real diagnostic situation.

The practical exam is the real filter. It checks what no multiple-choice test can: reading an actual building, spotting what is not visible from the middle of the room, and properly documenting what you saw and what you could not see. Candidates from a construction background revise the theory and treat the fieldwork as a given; candidates retraining from office jobs do the opposite. Both fail, for symmetrical reasons.

A reminder: certification is obtained domain by domain. There are six — energy performance, asbestos, lead, termites, gas, electricity — and each has its own exams. We cover them in our overview of the six certification domains.

Step 4 — What must be settled before the first assignment

Certification attests competence. It is not enough to practise. Two obligations come with it:

• Insurance. The professional must take out insurance covering the consequences of liability arising from their assignments. The imbalance built into the trade justifies the requirement: a survey is billed in tens or hundreds of euros, while an erroneous survey can cost far more.
• Independence. The diagnostician must have no link liable to compromise their impartiality and independence, either with the owner or their agent, or with a firm that might carry out the works. That closes the door on the most tempting arrangements: a survey “offered” by the company that will sell the works, a commission paid by an introducer.

Finally, holders of a valid certification appear in an official public register available online, listing their domains and certification body. Your status is public: an expired certification shows.

What research says about the trade

Two useful perspectives before starting out.

On the economic value of such schemes, economist Morris M. Kleiner, in “The influence of occupational licensing and regulation” (IZA World of Labor, 2015), distinguishes licensing — which bars practice without a title — from certification, which is more flexible, and notes that consumers may be willing to pay more for a certified practitioner. French property diagnostics clearly falls into the first regime: without certification, the activity cannot be validly performed.

On the technical difficulty of the DPE (diagnostic de performance énergétique, the French energy performance survey), the study by Bérangère Lartigue, Laura Biewesch, Flore Marion, Erica Cochran and Françoise Thellier, “Energy performance certificates in the USA and in France—a case study of multifamily housing” (Energy Efficiency, 2022), compares the French DPE with the American Energy Star score and shows how heavily modelling conventions and input-data quality weigh on the result (see the study). In other words: rigour on site is not a methodological detail, it is what makes the document worth anything.

How many domains should you target at first?

The temptation is to go for all six at once. That is rarely the right call: each domain carries its own training cost, its exams, then its monitoring and its recertification at seven years. Better to start from the domains actually in demand in your catchment area and extend later — bearing in mind that the “with mention” asbestos and lead certifications open a less crowded segment, that of pre-works and pre-demolition surveys, which we cover in this article.

Take action

Start with the one thing you cannot undo: get an accredited certification body to confirm in writing the prerequisites applying to your profile for your target domains, before enrolling in any course. Our Property diagnostician certification page summarises the scheme, the steps and the reference texts, and gives access to our full downloadable guide.