Which property inspections are truly mandatory before selling an old property?

Selling an old real estate property requires the seller to provide precise technical documentation to the potential buyer. To sell an old property, seven mandatory property inspections are required: the energy performance certificate (DPE), the lead exposure risk assessment (CREP), the asbestos report, the condition of electrical and gas installations, the report on the presence of termites and the natural and technological hazards report (ERNT). These documents, grouped together in the technical inspection file (DDT), protect both the seller and the buyer. Let's decrypt each inspection together to understand their scope and specificities.

The energy performance certificate (DPE)

Since 2006, the DPE has been one of the most consulted diagnostics by buyers. It evaluates the energy consumption of the property and its impact in terms of greenhouse gas emissions. The property receives a rating ranging from A (very efficient) to G (very energy-intensive), information that is now mandatory in all real estate listings.

The July 2021 reform profoundly modified the DPE calculation method, making it now legally enforceable. This means that a buyer can take action against the seller if the information proves to be incorrect. The validity period of the DPE is 10 years, except for those carried out between 2013 and 2021 which follow a progressive expiration schedule.

The lead exposure risk assessment (CREP)

The CREP concerns exclusively properties built before January 1, 1949. This obligation aims to detect the presence of lead in old paints, a toxic substance particularly dangerous for children and pregnant women.

The inspector measures lead concentration using an X-ray fluorescence device on all coatings of the property. If no trace of lead is detected, the diagnostic has unlimited validity. Conversely, if lead is present, the CREP must be renewed at each transaction and its validity is limited to one year.

The pre-sale asbestos inspection

All buildings whose building permit was issued before July 1, 1997 must undergo identification of materials containing asbestos. This material, widely used in construction for its insulating properties and fire resistance, proved to be highly carcinogenic.

The inspector examines the private parts of the property as well as common areas if it is a condominium. The inspection covers false ceilings, floor slabs, ducts, pipe insulation and other elements likely to contain asbestos. If the diagnostic reveals no presence of asbestos, its validity is unlimited. Otherwise, periodic inspections are necessary depending on the condition of the materials.

The inspections of interior installations

The electrical inspection

For electrical installations over 15 years old, a diagnostic is required. It verifies the compliance and safety of the internal electrical network, identifying potential risks such as lack of grounding, unprotected conductors or obsolete protective devices. This diagnostic is valid for 3 years and aims to prevent domestic accidents related to electricity, the leading cause of fire in old homes.

The gas inspection

Similar to the electrical diagnostic, the condition of the internal gas installation concerns installations over 15 years old. It checks the compliance of appliances, ventilation, piping and safety devices. The validity of this diagnostic is also 3 years. The main objective remains the prevention of risks of carbon monoxide poisoning and explosion.

The report on the presence of termites

This diagnostic is mandatory only if the property is located in an area declared at risk by prefectural order. Termites represent a serious threat to the integrity of wooden structures buildings. The inspector examines accessible wooden elements without demolition, as well as the immediate surroundings of the building.

This diagnosis has the particular characteristic of having a very short validity period: only 6 months. This brevity is explained by the rapid spread of termite colonies. In case of detection, the owner must file a declaration with the town hall and undertake treatment work.

« The file of technical diagnostics constitutes essential legal protection for the seller, who thereby protects itself against potential claims for hidden defects, and for the buyer, who has complete information about the actual condition of the property. »

The report on risks and pollution (ERP)

Formerly called ERNT, the state of risks and pollution informs the buyer about the natural, mining, technological, seismic and radon risks to which the property is exposed. This document is based on prefectural decrees and risk prevention plans of the municipality.

The seller can establish this document themselves by consulting information available at the prefecture or on official websites. Its validity is 6 months. The ERP must also mention whether the property was subject to compensation following a recognized natural or technological disaster.

Summary table of mandatory inspections

Complementary inspections according to situations

Beyond the seven systematic diagnoses, certain particular situations may require additional inspections. For properties equipped with a non-collective sanitation system, a septic tank diagnosis is mandatory. Similarly, if the property has a wood installation (fireplace, insert), a chimney sweep certificate may be required.

Properties located in the surveillance zone for dry rot (wood-eating fungus) may also require a specific inspection, although this diagnosis is not yet generalized throughout the entire territory. Some municipalities have established this obligation by municipal order.

Who carries out the inspections and at what cost?

All property diagnoses must be carried out by a professional certified by an accredited organization. This certification guarantees the technical competence of the inspector and covers their professional liability. The seller remains free to choose their service provider and can compare quotes.

The total cost of the DDT varies considerably depending on several factors:

• The size of the property
• Its geographical location
• The year of construction
• The number of necessary diagnoses
• The rates charged by the inspector

For an older apartment, you generally need to budget between 200 and 400 euros for all diagnoses. For a single-family home, the budget can reach 500 to 800 euros, or even more for large properties or those requiring complex investigations.

The consequences of an incomplete or incorrect DDT

The absence of a mandatory diagnostic at the time of signing the preliminary contract or the authentic deed exposes the seller to legal and financial sanctions. The buyer may request the cancellation of the sale or demand a reduction in the sale price.

If a diagnostic proves to be inaccurate and the buyer discovers after purchase a problem that was not reported, they can engage the liability of the certified diagnostician, but also that of the seller if voluntary concealment is proven. A claim for hidden defect remains possible for two years after the discovery of the defect.

« The accuracy of property diagnostics is a major issue of transparency in real estate transactions, helping to secure the market and strengthen trust between sellers and buyers. »

Practical tips for organizing your inspections

To optimize the process and control costs, several recommendations are necessary. It is wise to group all diagnostics with a single service provider who will generally offer an advantageous flat rate. Also plan to carry out these inspections sufficiently early, even before putting the property up for sale, to anticipate any corrective work.

• Verify the diagnostician's certification in the official directory
• Request several detailed quotes to compare
• Anticipate diagnostics 2 to 3 months before listing for sale
• Keep the reports in an accessible folder
• Inform the diagnostician of all improvements made

Some diagnostics may reveal anomalies requiring work. In that case, you have the choice between making the corrections before the sale or adjusting the price accordingly. A transparent strategy, including clear communication of identified defects, often accelerates negotiations and inspires confidence in potential buyers.

Secure your real estate transaction through inspections

The technical diagnostics file represents much more than a simple administrative formality. It constitutes the foundation of a transparent and secure real estate transaction, protecting the interests of all parties. For the seller of an older property, anticipating the preparation of this file allows you to approach the negotiation with peace of mind, avoid unpleasant surprises and enhance the value of your property. The initial investment in quality diagnostics always proves worthwhile, avoiding subsequent disputes and litigation. By scrupulously respecting these legal obligations, you demonstrate your professionalism and considerably facilitate the purchase process for your future buyers.