Increase in the council tax surcharge in 2026: Renting out a room long-term to make your property pay for itself

Do you own one or more empty rooms in your main home, or do you own a second home that you rarely use? Beware: the year 2026 marks a major and particularly punitive fiscal turning point for under-occupied spaces. With the increase in local taxation, keeping square metres unused is becoming a real financial drain. At Roomlala, we support thousands of hosts every day who are looking for solutions to optimise their budget. In this article, we will explain in detail how renting out a room, whether to a student or a young professional, not only allows you to offset the explosion of the 2026 council tax surcharge, but also to generate additional income that is entirely tax-free under certain conditions. Discover our complete guide to transforming this fiscal constraint into a genuine financial and personal opportunity.

Understanding the explosion of the 2026 council tax surcharge and its impact on your budget

The year 2026 does not look promising for owners of second homes or under-occupied housing. Indeed, the calculation basis for council 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 council tax for main residences would provide permanent relief, the reality is quite different for properties considered secondary or vacant.

Read also: Cedolare Secca 2026: The tax benefits of renting out a student room in Italy, New CIN sanctions in Italy: Why hosts are turning to shared housing in 2026 and 2026 university term in Italy: Everything you need to know about the student contract (Contratto per Studenti)

The real blow comes from the massive expansion of the famous "tax housing" restricted zone. Today, nearly 3,700 French communes are officially classified as restricted 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 council tax for second homes. This increase can fluctuate freely between 5% and 60%, depending on the municipal council's vote. The aim of the public authorities is clear: to discourage under-occupation and force the return of housing to the market for local residents.

To illustrate this phenomenon, let us take a concrete example. Imagine that you own a beautiful apartment in Annecy or a family home on the Basque coast, areas that are now ultra-restricted. If your council tax was 1,000 euros, the 3.9% increase in the base first raises 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 therefore becomes a luxury that many can no longer afford. This is where an intelligent rental strategy is essential to neutralise this burden.

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

Faced with this unprecedented fiscal pressure, the most effective and socially responsible solution is to put these vacant spaces back on the long-term rental market. At Roomlala, we observe that it is not necessary to rent out your entire home to make your property profitable. Renting out a single furnished room in your home helps to meet the housing shortage while completely cancelling out or significantly offsetting the council tax surcharge. Depending on your situation and that of your property, several types of leases are available to you to maintain a certain level of flexibility.

The host mobility lease: flexibility and profitability

The host mobility lease is a recent legal invention that is attracting more and more hosts. It is a short-to-medium-term furnished rental contract, lasting 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 missions. The immense advantage of this lease is its flexibility. It allows you to rent out your room during periods when you do not need it, while regaining the use of your property on a fixed date known in advance.

Let us take a very common case at Roomlala: you are the owner of a large apartment in Bordeaux, a city subject to a high "tax housing" restricted zone. You can rent a room in your home to a young professional on a trial period 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 reclaim your room 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: constantly growing rental demand

If you are looking for stability over a full academic year, the 9-month student lease is the ideal solution. The student housing crisis is a striking reality in all major French university metropolises. By opting for this type of rental, you provide an invaluable service to a young person in training 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, which guarantees you will get your space back for the summer season.

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

Renting a room in your home: taxation guide for tax exemption 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 inside your main home, you can benefit from a total income tax exemption on the rent received. Yes, you read that correctly: 100% of the income generated can be tax-free. However, the tax authorities impose strict rules that must be followed to maintain this invaluable advantage in 2026.

The first sine qua non condition is that the rented room must be an integral part of your main home. This means that it must not be totally 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 part of your house, even if the tenant has access to a shared bathroom or kitchen. In addition, the room must constitute the tenant's main residence (case of the student) or their justified temporary residence (case of the mobility lease or seasonal worker).

2026 rent caps that must be strictly respected

To avoid abuse and guarantee affordable rents, the State sets annual rent caps that must not be exceeded to benefit from the "renting a room in your home" tax exemption. For the year 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 at 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), i.e., a maximum monthly rent of approximately 268 euros excluding charges. If this same 15 m2 room is located in Toulouse (another region), the annual cap will be 2,385 euros (15 m2 x 159 euros), i.e., approximately 198 euros per month excluding charges. Major point of vigilance: 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 scheme. At Roomlala, we advise you to adjust your rent carefully to take advantage of this highly beneficial tax niche.

Procedures, standards, and safety: what you need to know before starting

While renting a room in your main home 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 restricted zones, the change of use of a property (moving from a second home to a tourist furnished rental or specific long-term rental) may require a 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 perfect 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 room in a homestay, the housing must respect standards of energy decency. The Energy Performance Certificate (DPE) of your home must not classify it among energy-inefficient properties (letters G, and soon F and E according to the government schedule). Ensure that your home is well-insulated and properly heated before signing a lease, otherwise the contract may be rendered void or you may 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 compliant with 2026 legislation, whether for a student lease or a mobility lease. For example, Marie, a Roomlala host in Montpellier, was able to rent out the room of her son who had moved abroad in just a few clicks. Thanks to our secure messaging system, she selected a trusted young PhD student, signed a digital student lease, and now receives tax-free rent that allows her to calmly finance renovation work on her house, far from the worries of the council tax surcharge.