Rise in the council tax surcharge in 2026: Rent out a room long-term to make your home pay for itself

Do you have one or more empty rooms in your main home, or do you own a holiday home that you rarely use? Be careful, 2026 marks a major and particularly punitive fiscal turning point for under-occupied spaces. With local taxes increasing, keeping unused square metres is becoming a real financial burden. At Roomlala, we support thousands of hosts every day who are looking for ways to optimise their budget. In this article, we explain in detail how renting out a room, whether to a student or a young professional, can not only offset the surge in the 2026 housing surcharge but also generate additional income that is entirely tax-free under certain conditions. Discover our complete guide to turning this tax burden into a real financial and personal opportunity.

Understanding the 2026 housing surcharge surge and its impact on your budget

2026 does not look promising for owners of holiday homes or under-occupied properties. The basis for calculating the housing tax on second homes (THRS) is subject to a flat-rate increase of at least 3.9%. This mechanical increase in the tax base significantly inflates local taxation, even before municipalities vote on their own rates. If you thought that the abolition of the housing tax for primary residences would provide permanent relief, the reality is quite different for properties considered secondary or vacant.

See also: Cedolare Secca 2026: Tax benefits for renting out a student room in Italy, New CIN regulations in Italy: Why hosts are turning to shared housing in 2026 and 2026 university intake in Italy: Everything you need to know about the student contract (Contratto per Studenti)

The real blow comes from the massive expansion of the so-called "tight housing zone" surcharge. Today, nearly 3,700 French municipalities are officially classified as tight zones. These municipalities, facing an acute housing crisis and severe difficulties in accessing rentals for permanent residents, now have the legal power to apply a dizzying surcharge on the housing tax for second homes. This surcharge can range freely between 5% and 60%, depending on the city council's vote. The public authorities' objective is clear: to discourage under-occupation and force the return of homes to the market for local residents.

To illustrate this phenomenon, let's look at a concrete example. Imagine you own a beautiful apartment in Annecy or a family home on the Basque coast, areas that are now ultra-tight. If your housing tax was 1,000 euros, the 3.9% base increase first brings it to 1,039 euros. If the town hall decides to apply the maximum surcharge of 60%, your final bill will climb to over 1,660 euros! Keeping an empty room or an unoccupied home for a large part of the year is therefore a luxury many can no longer afford. This is where an intelligent rental strategy is essential to neutralise this cost.

The strategic solution: transforming your empty space into a long-term rental

Facing this unprecedented fiscal pressure, the most effective and community-minded solution is to put these vacant spaces back onto the long-term rental market. At Roomlala, we have found that you don't need to rent out your entire home to make your property profitable. Renting out a simple furnished room in your home helps meet the housing shortage while completely cancelling or largely offsetting the housing surcharge. Depending on your situation and that of your property, several types of leases are available to you to maintain some flexibility.

The owner mobility lease: flexibility and profitability

The owner mobility lease is a recent legal invention that is increasingly appealing to hosts. It is a furnished rental contract for short to medium stays, ranging from 1 to a maximum of 10 months, and is non-renewable. It is strictly reserved for tenants in a situation of temporary mobility: professional training, higher education, apprenticeship contracts, internships, or temporary work assignments. The huge advantage of this lease is its flexibility. It allows you to rent out your room during periods when you don't need it, while regaining use of your property at a fixed and pre-determined date.

Let's take a very common use case at Roomlala: you own a large apartment in Bordeaux, a city subject to a tight housing zone surcharge. You can rent a room in your home to a young professional on probation or a seasonal worker for 6 months via a mobility lease. You thus generate rental income that largely covers your property tax and any potential surcharge, while keeping the freedom to take your room back to host your family during the summer holidays. Furthermore, this lease does not require a security deposit, which greatly facilitates the search for tenants, who are often covered by the Visale guarantee.

The student lease: growing rental demand

If you are looking for stability over a full school year, the 9-month student lease is the ideal solution. The student housing crisis is a striking reality in all major French university cities. By opting for this type of rental, you provide an invaluable service to a young person in education while ensuring regular income from September to May or June. At the end of the 9 months, the lease ends automatically without you needing to give notice, guaranteeing that you get your space back for the summer season.

For example, if you live in Lyon or Rennes and your children have left the family nest, their old bedrooms represent untapped financial potential. By hosting a student, you not only bring life to your home, but you also create an often very enriching intergenerational bond. Financially, the rent received over 9 months is more than enough to wipe out the impact of the 2026 housing surcharge, turning a cost centre into a real profit centre.

Homestay taxation: the guide to being tax-exempt in 2026

One of the best-kept secrets in real estate lies in Article 35 bis of the General Tax Code (CGI). If you decide to rent out a furnished room located within your primary residence, you can benefit from a total exemption from income tax on the rent received. Yes, you read that right: 100% of the income generated can be tax-free. However, the tax authorities impose strict rules that must be followed to maintain this invaluable benefit in 2026.

The first condition is that the rented room must be an integral part of your main home. This means it must not be completely independent. For example, an outbuilding at the bottom of the garden with its own entrance, its own meter, and which does not communicate with your living space will not benefit from this tax exemption. The room must be a room in your house, even if the tenant has access to a shared bathroom or kitchen. Furthermore, the room must constitute the tenant's main residence (the student case) or their justified temporary residence (the mobility lease or seasonal worker case).

2026 rent caps to strictly observe

To avoid abuse and ensure affordable rent, the State sets annual rent caps that must not be exceeded to benefit from this homestay tax exemption. For 2026, these annual caps excluding charges have been re-evaluated. They are set at 215 euros per square metre of living space in the Île-de-France region, and 159 euros per square metre in other French regions. It is crucial to calculate your rent precisely so as not to cross this red line.

Here is a concrete calculation example to help you. If you rent a 15 m2 room in Paris (Île-de-France), the annual rent excluding charges must not exceed 3,225 euros (15 m2 x 215 euros), which is a maximum monthly rent of approximately 268 euros excluding charges. If this same 15 m2 room is in Toulouse (another region), the annual cap will be 2,385 euros (15 m2 x 159 euros), or approximately 198 euros per month excluding charges. Major warning: if you set a rent that exceeds these 2026 legal caps by even one euro, the tax exemption is simply cancelled. All your rental income will then become taxable, generally under the micro-BIC scheme (with a 50% allowance) or the actual regime. At Roomlala, we advise you to carefully adjust your rent to take advantage of this highly beneficial tax niche.

Steps, standards, and security: what to know before getting started

While renting out a room in your primary residence is relatively simple administratively, transforming an entire second home or part of one into a long-term rental requires some precautions. In many cities located in tight zones, the change of use of a property (moving from a second home to a tourist rental or specific long-term rental) may require prior declaration at the town hall. It is essential to contact your local authority's urban planning department to ensure that your approach is in full compliance with the local urban plan (PLU).

Furthermore, regulations on energy performance have hardened considerably. To put a property on the long-term rental market, even if it is a homestay, the home must meet decency standards for energy. Your home's Energy Performance Certificate (DPE) must not classify it as a thermal sieve (letters G, and soon F and E, depending on the government schedule). Ensure that your home is well-insulated and properly heated before signing a lease, otherwise the contract could be declared null and void, or you could face sanctions.

Finally, starting to rent out a room can raise legitimate concerns. This is precisely why Roomlala exists. We provide you with a secure platform to publish your listing, verify the profile of your future tenants, and manage payments with complete peace of mind. We also provide you with lease templates that comply with 2026 legislation, whether it is a student lease or a mobility lease. For example, Marie, a Roomlala host in Montpellier, was able to rent out her son's room while he was abroad in just a few clicks. Thanks to our secure messaging system, she selected a trustworthy young PhD student, signed a digital student lease, and now receives tax-free rent that allows her to calmly fund renovation work on her house, far from the hassle of the housing surcharge.