The gross yield displayed in an advertisement predicts nothing. What determines the actual performance of a rental investment is the mastery of three variables: the differential between market rent and actual charges, the applicable tax regime, and the holding period. Here we detail the technical arbitrations that separate a profitable project from a wealth sinkhole.
Thermal sieves removed from the market: a direct effect on rental profitability
The ban on renting G-rated housing since 2023 and then F-rated housing since 2025 has removed a significant fraction of the rental stock. This contraction in supply maintains pressure on rents in tight areas and mechanically improves the profitability of energy-efficient properties.
For an investor, this means that a property rated D or better in an area where supply is dwindling benefits from a double advantage: rent supported by demand, and no short-term energy renovation work required. Conversely, acquiring a property rated E or lower requires budgeting for a renovation envelope that can absorb several years of positive cash flow.
The supply of rental housing is expected to grow by about 12.5% in the first half of 2026 compared to 2025, but this recovery does not compensate for the persistent shortage of small units, where rental pressure remains high. We recommend targeting well-rated studios and T2 apartments in university metropolitan areas, where applications per property remain high. Resources like the All In Investissements website allow for comparing available property types across various rental markets.
Net profitability after tax: the only reliable indicator in rental investment
Gross profitability (annual rent divided by purchase price) is a first-level filter. It does not reflect actual performance. Net profitability deducts property tax, non-recoverable charges, PNO insurance, management fees, and provision for vacancy. Net-net profitability additionally incorporates applicable taxation.
It is on this last indicator that the difference between a viable project and an investment that destroys capital is played out.
Micro or real regime: an arbitration worth several thousand euros per year
In furnished rentals under the micro-BIC regime, the flat-rate deduction remains easy to manage but prevents the deduction of actual charges, depreciation of the property, and furniture. Under the real regime, the accounting depreciation of the building and furniture can neutralize taxation on rental income for about ten years.
We observe that the real regime almost systematically becomes more advantageous as the annual amount of charges, loan interest, and depreciation exceeds the threshold of the flat-rate deduction. Run a simulation with an accountant before checking a box on your tax return.
- Micro-BIC: flat-rate deduction, simplified management, but no deduction of actual charges or depreciation.
- Real regime: full deduction of charges, depreciation of the property and furniture, annual accounting obligation.
- SCI under corporate tax: property depreciation, taxation of profits at the corporate tax rate, but capital gains calculated on the net book value upon resale (heavy taxation on exit).
Tenant stay duration: the hidden variable of rental yield
Vacancy is the main destroyer of yield. One month without rent out of twelve reduces gross profitability by about 8%. Two months, and the monthly cash flow often turns negative.
A recent data point sheds light on this issue: the average length of tenant stay has increased from about 28 to nearly 38 months between 2019 and 2025, a one-third increase. This trend mechanically reduces turnover rates and associated costs (refurbishment, vacancy between leases, agency fees).
Target stable profiles rather than increasing the face rent
Setting a rent slightly below the market ceiling attracts more applications and allows for the selection of solid files. A tenant who stays three years with a rent 5% lower generates more net income than a succession of short leases interspersed with vacancy and re-letting costs.
The objective selection criteria remain the effort rate (rent less than a third of net income), professional stability, and the presence of a guarantor or a GLI-type guarantee.
Rent increases in 2026: what recent figures change for investors
Free sector rents are rising in France with an average increase of about 2.6% year-on-year as of July 1, 2026, and even more in Paris. This increase, which exceeds the inflation observed over the same period, supports the real yield of properties already in the portfolio.
For new acquisitions, this rent increase does not automatically compensate for high purchase prices. We recommend reasoning in terms of price per square meter relative to the achievable monthly rent, rather than in theoretical gross yield calculated on an “optimistic” rent.
- Check the actual median rent in the municipality via local observatories (ADIL, approved rent observatories) before establishing a forecast.
- Incorporate rent control in the affected cities: exceeding the increased reference rent exposes you to a tenant appeal and retroactive repayment.
- Anticipate the annual revaluation indexed to the IRL, which caps rent increases during the lease.
A profitable rental investment in 2026 relies less on the displayed gross yield than on the ability to maintain a high occupancy rate, choose the right tax regime, and target properties whose energy performance guarantees medium-term rental viability. The best investment is one where the cash flow remains positive even with one month of vacancy per year.