Purchasing a second residence is often a mix of excitement and uncertainty. While the allure of a seaside villa or a mountain chalet can be strong, the financial stakes are equally high. Conducting a thorough due-diligence process before signing the preliminary contract is the only way to turn that dream into a secure investment.
This guide condenses the essential checks into a single, easy-to-follow checklist. By examining cadastral data, urban permits, technical installations, and condominium obligations, you can spot hidden liabilities early and use them as leverage during price negotiations.
1. Cadastral and urban-planning verification
The first step is to obtain the cadastral report and the current plan of the property. Verify the owner’s name, cadastral class, taxable value and the declared surface. Compare the official plan with the actual layout of the house; any mismatch—such as a missing wall or an extra room—must be clarified with a licensed surveyor, who will advise whether a cadastral amendment is mandatory.
On the urban side, request all building permits that have been issued over the years: the original construction licence, any subsequent SCIA or DIA approvals for extensions, and the certificate of habitability (SCA). Check that the present configuration of the dwelling complies with the approved projects. If the property includes terraces, lofts or re-converted spaces, a technical site visit is advisable to confirm that the works were legally authorised.
2. Technical systems and safety compliance
Electrical, gas, plumbing and heating plants represent both safety concerns and future expenses. Ask for the compliance certificates (or conformity reports) for each system, as well as the maintenance logbooks. Verify the presence of residual-current devices, proper grounding, ventilation of technical rooms and safe evacuation routes for flues and chimneys.
When documentation is missing or outdated, schedule a functional test: turn on the heating, run the water, and, if possible, request a qualified engineer to perform an energy audit. The results will allow you to estimate the cost of necessary upgrades—insulation, double-glazed windows, or a new boiler—and to factor those figures into your offer.
3. Condominium obligations and financial health
If the unit belongs to a condominium, three sets of papers must be examined: the condominium bylaws the millesimal table that defines each owner’s share of expenses, and the minutes of the last general assemblies. These documents reveal rules about short-term rentals, pet ownership, noise restrictions, and any pending works on the façade or shared installations.
Review the most recent budget, the actual expenses, and the reserve fund status. Identify any arrears, ongoing legal disputes, or upcoming extraordinary expenses that could affect your cash flow. For buildings with centralised heating or water distribution, request the supply contracts and the allocation method used for shared costs.
4. Red flags and negotiation levers
Several warning signs should trigger a deeper investigation: undocumented extensions, missing habitability certificates, obsolete or absent plant conformity documents, visible deterioration of common areas, and any recorded legal liens or mortgages. Sudden price reductions, the seller’s hesitation to provide paperwork, or inconsistencies between cadastral data and reality are also strong indicators of hidden risk.
When such issues surface, use them to reshape the deal. Attach a price reduction clause linked to the cost of required regularisation, introduce a conditional clause that releases the escrow until all permits are obtained, or negotiate a partial hold-back on the final payment to cover future repairs. A well-documented due-diligence report, supported by independent cost estimates, strengthens your bargaining position and protects you from unexpected expenditures after the sale.
By mastering these steps, you turn a second-home dream into a solid, low-risk asset.
