Differences between an architect, an interior architect, and an interior designer
As part of a turnkey renovation or a collaboration with an interior renovation company, it’s common to work with an architect, an interior architect, and/or an interior designer.
Each of these professionals has distinct skills and a specific scope of intervention.
- An architect is primarily qualified to manage structural work involving the building’s framework—such as new construction, extensions, and major alterations.
- An interior architect typically handles secondary work that transforms and arranges a living space without altering the building’s structural elements.
- An interior designer mainly focuses on finishes, with the goal of enhancing or harmonizing a living space without changing its layout.
The involvement of an architect, an interior architect, and/or an interior designer will depend on the type of work required during the renovation of an apartment or the renovation of a house.
To help you gain clarity, Maison Kyka breaks down the role of each professional, so you can plan your renovation project under the best possible conditions.Looking for tailored advice? Tell us about your project using our simulator below.
The architect is responsible for all work involving the structure of the building
Training and regulation of the architect profession
The title of architect is protected by the French law of January 3, 1977 on architecture. It may only be used by professionals who hold a state-recognized degree and are registered with the Ordre des Architectes (National Order of Architects). This official body ensures the competence, independence, and ethical standards of the profession.
To become an architect, one must acquire the technical, legal, and aesthetic skills required to design and carry out architectural projects:
- Initial training (5 years) at a National School of Architecture (ENSA) or an accredited institution, leading to a state-recognized degree equivalent to a Master’s level (Bac +5).
- The HMONP (Authorization to Practice Project Management) allows architects to work independently, sign architectural plans, and oversee construction sites. This professional certification is completed over one year through a work-study program.
- Swearing-in and registration with the Ordre des Architectes: once graduated and officially certified, the architect takes an oath and is registered with the Ordre des Architectes. They can then take full responsibility, under their own name, for the entire scope of an architectural project.
A DPLG architect holds the same professional rights as an HMONP architect. The former title, DPLG (Diplômé Par Le Gouvernement), is still recognized by the French state, although it has not been awarded since 2007.
What types of work should be entrusted to an architect?
The architect is the qualified professional authorized to design an entire building, modify its structure, and coordinate the various stages of a construction project—whether it’s a new construction or an ancient property.
1. Comprehensive architectural design
The architect envisions the layout of volumes, room distribution, circulation paths, facades, openings, and more broadly, the balance between functionality, aesthetics, and energy performance. They take into account your needs, the technical constraints of the site, and the regulatory framework.
2. Execution of structural (shell and core) work
The architect is qualified to work on the structural elements of a building. For example, they can:
- open a load-bearing wall to create a large living area,
- design an extension or a vertical addition (building upward),
- modify floor slabs, beams, or the roof structure.
They ensure the technical feasibility of the work and guarantee the structural stability of the building. They may also collaborate with specialized engineering firms to carry out structural calculations when needed.
3. Management of administrative procedures
The architect is authorized to prepare and submit building permit applications or prior declarations of work. They can also represent you in dealings with urban planning authorities to help streamline the process.
4. Project management and site coordination
If authorized to provide project management services, the architect oversees every phase of the construction site, ensuring that timelines, budgets, and execution quality are respected.
The architect may work independently or rely on a network of specialized partners (thermal engineers, structural engineers, geotechnical experts). They can also collaborate with an interior architect or an interior designer when the project includes an aesthetic or interior comfort dimension.
Why hire an architect?
Hiring an architect means ensuring that every decision is based on solid technical, legal, and regulatory foundations.
They are well-versed in the urban planning regulations of your municipality, including the constraints of the Local Urban Plan (PLU), thermal standards (RE2020), and accessibility requirements. This in-depth knowledge of the regulatory framework is translated into practical solutions when purchasing a property requiring renovation, helping to avoid administrative pitfalls and increasing the long-term value of the real estate asset.
An architect is also the only professional legally authorized to work on large-scale projects. In France, the law requires the involvement of an architect registered with the Ordre des Architectes for any project with a floor area exceeding 150 sq. m. This legal obligation is set forth in Article R*431-2 of the French Urban Planning Code.
Failing to submit a building permit for this type of work is a violation of the Urban Planning Code and can result in suspension of the construction site, heavy fines, or even demolition of the structure.
Hiring an architect can also be a guarantee of safety. According to Article 1792-1 of the French Civil Code, the architect holds the legal status of a builder. As such, they are liable for any serious defects or damage that could compromise the structural integrity of the building for ten years after completion (Spinetta Law). Working with an architect therefore provides dual insurance coverage: a construction damage insurance (assurance dommage-ouvrage) and a ten-year liability insurance (assurance décennale).
However, their scope of intervention is limited when it comes to interior layout and decoration. If your project involves detailed spatial transformation, a personalized atmosphere, or a high level of aesthetic support, the architect can collaborate with an interior architect or an interior designer.
What is the cost of hiring an architect?
The cost of hiring an architect can vary significantly depending on the scale of the project, the complexity of the work, and the nature of the services required.
1. Percentage-based fees
The most common method of compensation for architects on construction or major renovation projects is percentage-based. The architect typically earns between 8% and 15% of the total cost of the work, depending on the technical complexity of the project, the scope of services provided, and the location of the property.
2. Flat fees for one-time or limited-scope projects
For simpler projects—such as an extension, a design-only mission, or the preparation of a building permit application—a flat fee can be set in advance. Prices generally start at a few thousand euros. This option allows you to keep costs under control while still benefiting from an architect’s expertise.
The fees applied by Maison Kyka are complemented by the involvement of partner architects when the project requires it, thus ensuring a turnkey experience regardless of the scale of the works.
The interior architect transforms the interior space
Training and regulation of the interior architect profession
Unlike the title of architect, the title of interior architect is not protected by law. As a result, there are no strict regulations governing its use—meaning that, in theory, anyone can claim the title.
However, certain recognized training programs within the industry do provide legitimacy for practicing this profession:
- The BTS in Spatial Design (BTS Design d’espace) trains students in design techniques, 3D software, and principles of interior layout, leading to a degree equivalent to two years of post-secondary education (Bac +2).
- Advanced degrees such as the DSAA (Diplôme Supérieur d’Arts Appliqués), the DNA (Diplôme National d’Art) with a design focus, or programs offered by architecture and design schools provide a more in-depth approach to the aesthetic, technical, and cultural aspects of spatial design. These programs range from three to five years of post-secondary education (Bac +3 to Bac +5).
- Professional certifications (RNCP) or private training programs specialized in spatial design or interior decoration are also available, particularly for those pursuing a career change or seeking to specialize in the field.
Some institutions are members of the Réseau des Écoles Françaises d’Architecture Intérieure (RÉFAI), which ensures a high standard of academic and professional training.
Although no official registration with a professional order is required, the CFAI (French Council of Interior Architects) plays a key role in professional recognition. It grants accreditation to experienced interior architects after reviewing their education, professional experience, and portfolio of completed projects. This accreditation serves as a mark of competence, reliability, and adherence to ethical standards.
Which Renovation Works Should You Entrust to an Interior Architect?
An interior architect designs, optimizes, and coordinates major interior renovation works, while ensuring an aesthetic coherence tailored to your lifestyle and tastes.
1. Reorganization and layout of the space
The interior architect improves functionality and flow within a home, notably by modifying or removing non-load-bearing partitions. For example, they may open up a kitchen to the living room to create a bright, welcoming living space, or add partitions to create an extra bedroom.
2. Oversight of secondary construction works
The interior architect is capable of managing all interior fit-out works. They design the plans, establish the specifications, select materials, and ensure the desired style is respected.
For example, they can:
- manage fluid and network works (electricity, plumbing, lighting),
- create technical rooms such as the bathroom or kitchen,
- choose floor and wall coverings,
- design custom storage solutions.
3. Integration of decorative aspects within the overall project
The interior architect does not merely design functional spaces: they define color harmonies, finishes, textures, and even the furniture to be integrated or custom-designed.
4. Site supervision and coordination
Within the scope of a full mission, they can take charge of interior project management. They select contractors, schedule interventions, and ensure that each craftsman adheres to the plans, deadlines, and finishing details.
When a project involves structural work (load-bearing walls, beams, floors, etc.) or requires a building permit, the interior architect cannot work alone: they must collaborate with a licensed architect or a technical engineering firm to ensure compliance and site safety.
Why hire an interior architect?
Hiring an interior architect means benefiting from a comprehensive vision of your living space, combining technical expertise, spatial planning skills, and aesthetic intelligence.
One of their greatest strengths lies in their ability to unlock the potential of an interior and completely rethink the organization of volumes—two aspects often underestimated by homeowners. They provide detailed 2D or 3D plans that allow you to visualize the project before work begins.
The interior architect possesses strong technical mastery of renovation sites: they are familiar with current regulations, constraints related to electrical, plumbing, or thermal systems, and know how to anticipate interactions between various trades.
For large-scale projects, particularly those exceeding 150 m² and requiring a building permit, the role of the interior architect reaches its limits. In such cases, it is essential to call upon a licensed architect—the only professional authorized to submit a permit application and covered by a ten-year liability insurance.
At Maison Kyka, each interior architect is supported by a renovation project manager who ensures the coordination of works and budget compliance. This duo guarantees smooth site management, from the initial meeting to final delivery, including the selection of craftsmen and the inspection of finishes.
“Excellent support throughout the search, plan design, furnishing, and project follow-up. Very professional team and an ideal offer for those who want to buy and completely rethink an apartment but lack the time to manage everything." Éloi Verspieren
What is the cost of an interior architect?
The fee of an interior architect varies depending on the level of customization expected and the scope of the assigned mission. Unlike an architect, who works on the building’s structure, the interior architect focuses on existing volumes, which often translates into more accessible costs—without compromising expertise.
In practice, two billing methods coexist:
- The study fee, the most common for design missions. The interior architect charges a fixed amount based on the area to be developed (often expressed in €/sq. m) or the project's complexity level. This fee generally covers the site visit, the study of specifications, the proposal of 2D/3D plans, and sometimes a shopping list or decorative moodboard.
- A percentage fee based on the construction costs may be added when the interior architect also oversees site supervision. This is usually calculated on the total amount of the works (generally between 5% and 12%). It includes coordination of craftsmen, verification of quotes, schedule management, and regular site visits up to final acceptance.
Before committing, clearly define the expected scope of the mission. This upfront clarity helps avoid unpleasant surprises on the final quote.
At Maison Kyka, we offer two transparent packages:
- The Maison Kyka Studio package, dedicated exclusively to interior renovation projects, priced between €1,550 and €2,000 /sq. m depending on the level of transformation desired.
- The Turnkey package, which combines property acquisition and renovation, with a fixed commission of 5% on the total project amount, including the purchase price with agency fees and the renovation package priced between €1,550 and €2,000 /sq. m.
These packages include personalized support throughout the creation of your dream home.
The interior decorator harmonizes and enhances a space
Training and professional framework of the interior decorator profession
The profession of interior decorator is neither regulated by law nor subject to strict professional regulations. In other words, anyone can practice this activity, even without a diploma, provided they have strong skills in design, visual arrangement, and client support.
That said, training is highly recommended to acquire the fundamentals of the profession:
- BTS in Study and Implementation of Interior Fit-Out, a Bac +2 level diploma, which prepares students in interior layout techniques, knowledge of materials, and the creation of technical plans.
- National Diploma of Art (DNA), design option, awarded by art schools, offering a more creative approach to space and equivalent to a Bac +3 level.
- Professional bachelor's degrees in fit-out or spatial design, accessible after a Bac +2, which often lead to project management roles or the creation of independent agencies.
- Private or online training programs, which enable career changers or self-taught individuals to structure their skills.
In this profession, experience, artistic sensitivity, and the ability to understand the client often outweigh formal diplomas. A strong portfolio, a refined culture, and genuine attentiveness to the client’s needs make all the difference.
Which renovation works should you Eentrust to an interior decorator?
The interior decorator intervenes when it comes to enhancing a space without altering its structure or architectural layout: their mission is primarily aesthetic.
1. Style and ambiance consulting
The interior decorator begins with an analysis of your interior, lifestyle habits, and aesthetic preferences. They then propose an overall decorative concept: bohemian, contemporary, industrial, Scandinavian, or more classic ambiance… Everything is designed to create visual harmony and coherence in each room.
2. Selection of furniture and accessories
They assist you in choosing furniture, lighting, curtains, rugs, and decorative accessories. Depending on your preferences, budget, and site constraints, they may for example:
- work with accessible brands,
- source rarer, high-end pieces,
- hunt for vintage items,
- and offer custom-made furniture.
3. Arrangement of the décor
Even without altering partitions, a skilled interior decorator knows how to optimize furniture arrangement to improve flow and highlight volumes. For example, they may position a sofa to open up a perspective or create a decorative focal point with a gallery wall.
4. Home staging or decorative makeover
In the context of a property sale or the need for an affordable refresh, the decorator proposes light but effective transformations: repainting a wall, applying graphic wallpaper, replacing cabinet handles, reorganizing wall décor, or modernizing lighting.
The decorator never intervenes on load-bearing walls, partitions, or technical installations. If a deeper renovation need is identified, they will refer you to an architect or interior architect. They provide the finishing touch to a renovation project or the starting point for a new ambiance in an already well-maintained home.
Why hire an interior decorator?
Hiring an interior decorator allows you to rethink the ambiance of a home without undertaking major renovations. This professional stands out for their aesthetic sense, design culture, and knowledge of trends, such as the comeback of wallpaper in decoration. They excel in creating unique atmospheres, notably through the use of color. They also help you avoid costly mistakes: an oversized sofa, a poorly chosen shade, or inappropriate lighting can quickly unbalance a room. In short: their strength lies in enhancing the existing without breaking everything.
However, an interior decorator neither has the right nor the skills to modify a building’s structure. They do not create technical plans, file for building permits, or supervise major works. That is why their role complements that of an architect or interior architect.
Finally, note that unlike architects, interior decorators are not legally required to have insurance and do not bear responsibility for the works.
What ss the cost of an interior decorator?
Hiring an interior decorator is often the most affordable option when it comes to transforming your interior without undertaking technical work.
The fees of an interior decorator vary depending on the nature of the mission, the surface area involved, and sometimes the level of customization requested. Several pricing methods are possible:
1. “Mood board” or “decor coaching” package
For a few hundred euros, the decorator provides you with an overall ambiance proposal, accompanied by a shopping list and layout advice. This is the ideal solution if you want to refresh a room without committing to a complex project.
2. Hourly or daily rate
Often used for one-off consultations at home, this billing method allows you to get an expert’s eye on your interior without further commitment.
3. Online package
Some platforms offer fully remote services that include analysis based on photos and plans, at a reduced cost. This format is suitable for small spaces or simple projects.
4. Commission on purchase
Some interior decorators receive a commission on furniture and decorative items purchased through their partner suppliers. This system does not directly affect your budget but may influence the selection offered.
Unlike an architect, the interior decorator does not assume technical responsibility and is therefore not subject to ten-year liability insurance. This explains their lower fees but also a different level of commitment.
Summary of the differences between an architect, an interior architect, and an interior decorator
It is not always easy to know which professional to turn to in order to successfully carry out a renovation or design project. To help you make the right choice, Maison Kyka offers you a summary table highlighting the main differences between an architect, an interior architect, and an interior decorator:
At Maison Kyka, we combine the expertise of these three professions into a tailor-made experience, from purchasing your property to the final decorative touches, including renovation.