The garden studio is increasingly popular with French homeowners looking for extra square metres without major extension works. In 2026, this type of standalone construction costs on average between €1,500 and €3,000 per m², depending on the finishes and the construction method chosen. Well planned, a garden studio can generate regular rental income, serve as an office or an additional bedroom, and increase the resale value of the main property. This article details the real costs, the administrative procedures, the applicable tax rules and the rental potential of a garden studio to help you assess whether this project is worthwhile.
In summary
- A garden studio costs between €1,500 and €3,000/m² on average, i.e. €30,000 to €75,000 for a 20 m² turnkey model.
- Below 20 m², a simple prior declaration of works (déclaration préalable de travaux) is sufficient; above that, a building permit (permis de construire) becomes mandatory.
- Renting out the studio (short-term, long-term, or as an office) can generate worthwhile additional income, but involves specific taxation under the BIC regime.
- Adding living space affects the property tax (taxe foncière) and can increase the value of the main property on resale, provided it is well integrated.
What Is a Garden Studio and Which Construction Types Can You Choose?
A garden studio is a standalone ancillary structure built in the garden of a house, intended for residential use, as an office, or for rental. Unlike a simple garden shed, it is fitted out to be habitable: thermal insulation, electricity and water connections, and sometimes a bathroom and a kitchenette. Three main families of solutions exist on the market, with significant differences in price and lead times.
Timber kit with frame or solid log construction
The timber kit garden studio remains the most common solution in France. Delivered as a kit or assembled by a professional, it offers a good compromise between price, appearance and thermal performance, with insulation compliant with the RE2020 regulations for recent models. Allow between €1,500 and €2,200 per m² for a timber kit of decent quality, installation included.
Modular units and converted containers
Modular studios, prefabricated in a factory then delivered and installed in a single day, make it possible to cut construction times to just a few weeks. The converted container, which is more unusual, appeals for its industrial look and robustness, but requires anti-corrosion treatment and reinforced insulation to remain comfortable in every season. Both options are generally in a range of €1,800 to €3,000 per m², depending on the level of finish.
What Is the Real Price of a Garden Studio in 2026?
The overall budget depends heavily on the surface area, the materials and the level of equipment. A non-habitable garden studio, without sanitary facilities or heating, can cost from €2,000 for a small model of a few square metres. Conversely, a habitable 20 m² studio, delivered and installed by a professional with foundations, timber frame, RE2020 insulation and double-glazed windows and doors, generally costs between €30,000 and €75,000 including VAT.
Factors that affect the price per m²
Several factors strongly influence the final cost: the type of foundations (concrete pads, ground beams or slab), the quality of the insulation, the presence of a bathroom and a fitted kitchen, the connection to utilities (electricity, water, sewerage), and the choice between self-building from a kit and a turnkey installation by a professional. Self-building can reduce the bill by 20 to 30%, but requires real technical skills.
Budget to plan for according to surface area
For a studio of less than 12 m², the budget often starts at around €15,000 to €25,000 for a simple habitable model. Between 15 and 20 m², allow €25,000 to €45,000. Above 20 m², with a building permit and full equipment, projects frequently exceed €50,000, or even €75,000 for high-end specifications.
What Administrative Procedures Are Required to Install a Garden Studio?
The installation of a garden studio is governed by the French town planning code (code de l'urbanisme), and the decisive threshold is 20 m² of floor area (surface de plancher) or footprint (emprise au sol).
Prior declaration or building permit?
For a garden studio with a floor area between 5 m² and 20 m², a simple prior declaration of works (déclaration préalable de travaux) filed at the town hall is sufficient, with a processing time of approximately one month. Above 20 m² (or 40 m² in certain urban zones covered by a PLU, subject to conditions), a building permit (permis de construire) becomes mandatory, with a processing time of two to three months. Below 5 m², no formalities are required, unless the height exceeds 12 meters.
Distance, PLU and local rules to check
Before filing any application, it is essential to consult the municipality's local urban plan (plan local d'urbanisme, PLU), which may impose rules on distances from property boundaries, aesthetic constraints (color, materials), or protected zones where construction is restricted or even prohibited. An architecte des Bâtiments de France (architect of the French national heritage buildings authority) may also be consulted if the land is located near a historic monument.
What rental potential does a garden studio offer?
A garden studio represents an opportunity to generate additional income, provided its use is clearly defined beforehand.
Short-term rental or traditional furnished rental
Many owners opt for short-term rental via platforms such as Airbnb or Booking, which is particularly profitable in tourist areas or near major cities. Long-term furnished rental, on the other hand, offers more predictable income stability, notably for housing a student, a young professional or a relative while maintaining one's independence. In both cases, the studio must be properly equipped and comply with the decency standards in force.
Office, independent bedroom or professional space
Beyond renting to third parties, a garden studio can also serve as a remote-working space separate from the main home, an independent guest room, or a space for a teenager seeking more autonomy. This personal use, while not generating direct income, improves quality of life and can be an appreciated selling point in a future transaction.
What impact on taxation and on the value of the main property?
Adding a garden studio changes the property's tax situation and may, under certain conditions, increase its value.
Development tax and property tax
Any new construction of more than 5 m² must be declared within 90 days of completion of the works, using the declaration of completion of works form. This declaration triggers the calculation of the development tax (taxe d'aménagement), a one-off tax paid only once, the amount of which depends on the taxable floor area and the flat-rate value set each year (around €890 per m² outside Île-de-France in 2026). It also leads to a revaluation of the property tax (taxe foncière), calculated on the basis of the new living area created.
Rental income: which tax regime to choose?
Income from renting a furnished garden studio falls under industrial and commercial profits (bénéfices industriels et commerciaux, BIC), under the status of non-professional furnished landlord (loueur en meublé non professionnel, LMNP) in the majority of cases. Two regimes are possible: the micro-BIC regime, with a simplified flat-rate allowance, suited to modest rental income, or the real regime (régime réel), which is more complex but allows the deduction of all actual expenses (depreciation of the construction, works, loan interest), and is often more advantageous for projects with a substantial budget.
A real lever for added value at resale
A garden studio that is well integrated into the grounds, compliant with planning rules and properly equipped can be a real asset at resale, particularly if it is presented as a versatile space (office, spare bedroom, rental accommodation). Conversely, an undeclared or poorly maintained structure can hinder a sale and expose the seller to administrative complications. Having a property valuation carried out before and after the works makes it possible to objectively measure the studio's impact on the overall value of the property.
How can you optimize the profitability of your garden studio?
For the garden studio to become a genuinely profitable investment and not merely a comfort expense, a few good practices are essential.
Choosing the location and orientation carefully
A south-facing garden studio with its own independent access and a degree of privacy from the main house is easier to rent out and adds more value than a poorly oriented building or one that is too close to the main dwelling. The distance from the road and the ease of connecting to existing utility networks also directly affect the final cost of the work.
Comparing quotes and anticipating hidden costs
It is advisable to request at least three detailed quotes that include the foundations, the utility connections and the interior finishing, which are often underestimated in entry-level offers. Anticipating ancillary costs (the taxe d'aménagement, the assurance dommages-ouvrage construction insurance, the electrical connection) also helps avoid unpleasant budget surprises during the project.
Conclusion
The garden studio is establishing itself as a flexible solution for gaining space, generating rental income or adding value to a property, provided that you keep control of your budget and scrupulously follow the administrative procedures. At between €1,500 and €3,000 per m², the investment remains substantial but can prove profitable over the long term, notably thanks to furnished rental or to the capital gain generated on resale. Before getting started, it is essential to assess your project, its tax treatment and its impact on the value of the main property precisely.
The expert's view
"The garden studio is one of the most interesting extension projects I have seen emerging among our clients in recent years, and for good reason. It allows you to add usable floor area without touching the structure of the main dwelling, with construction times that are much shorter than for a traditional extension. What strikes me is that many owners still underestimate the administrative procedures and the taxation that come with this type of construction: above 20 m², a building permit (permis de construire) becomes mandatory, and both the taxe d'aménagement and the taxe foncière must be anticipated from the initial budget. In terms of profitability, I find that the best-designed studios, with independent access, good insulation and a clearly defined rental use, are those that add the most value on resale. Conversely, an undeclared building or one that is poorly integrated into the plot can complicate a transaction. My advice is simple: before getting started, have your property valued with and without the planned studio, compare several quotes from builders, and systematically check the local planning rules with your town hall. It is this upfront preparation that makes the difference between a garden studio that remains a cost and a garden studio that becomes a genuine asset for your estate."
— Frédéric Rémy, Commercial Performance Director at Capifrance
FAQ - Frequently asked questions
Is a building permit required for a 20 m² garden studio?
No, up to 20 m² a simple prior declaration of works (déclaration préalable de travaux) is sufficient in most municipalities. A building permit (permis de construire) becomes mandatory above this threshold, subject to local exceptions linked to the PLU.
How much does a habitable 20 m² garden studio cost?
A habitable 20 m² garden studio, delivered and installed by a professional with foundations, insulation and fittings, generally costs between €30,000 and €75,000 including VAT, depending on the finishes chosen.
Does a garden studio increase the taxe foncière?
Yes, the floor area created must be declared within 90 days of the completion of the works, which results in a revaluation of the taxe foncière as well as payment of the taxe d'aménagement.
Can a garden studio be rented out as a short-term rental?
Yes, provided that local regulations are complied with and the income is declared under the industrial and commercial profits regime (BIC), most often as a non-professional furnished landlord (LMNP).
Does a garden studio really add value to a property on resale?
Yes, when it is well integrated, compliant with planning rules and properly maintained, a garden studio is seen as a versatile space that can strengthen the appeal of the property to buyers browsing property listings.
Author
Frédéric Rémy – Director of Sales Performance
A real estate professional with several years of experience within the Capifrance network, I would like to share essential advice with you to help you successfully complete your property project with our advisors.
