What is the Difference Between an Architect and an Interior Designer?
by Leslie Alexander, Co-Founder / Director
Table of Contents
Architect and Interior Designer: two distinct professions
Are you planning renovation or construction work and don't know which professional to turn to? Confusion between architect and interior designer is common, yet their fields of intervention differ fundamentally. Understanding these differences will help you choose the right contact and optimize your budget.
The architect designs buildings in their entirety: structure, facades, roof and exterior developments. The interior designer, on the other hand, focuses on transforming and optimizing existing interior spaces. If the former draws the building envelope, the latter reinvents its content.
In France, there are approximately 30,000 architects registered with the Order of Architects according to 2023 data from the National Council. The architect profession is strictly regulated, unlike that of interior designer which remains accessible without a mandatory protected title. This legal distinction has direct consequences on the guarantees offered to clients and the types of projects each professional can take on. Let's decipher these two complementary professions together to help you make the right choice.
What training to become an architect or interior designer?
The architect's path: minimum 6 years of study
To practice as an architect in France, a long and demanding curriculum is mandatory. Since the LMD reform of 2007, the DPLG architect title (Diplômé Par Le Gouvernement) has been replaced by the State Diploma of Architect (DE), obtained after 5 years of study at one of the 20 national schools of architecture (ENSA).
However, this diploma alone does not allow practicing project management independently. To sign a building permit and register with the Order of Architects, an additional year is required: the Authorization for Project Management in One's Own Name (HMONP). In total, 6 years of study are therefore required to fully practice the profession.
The interior designer's path: varied training
The interior designer generally follows 4 to 5 years of training at an art, design or interior architecture school. Unlike architects, their profession is not regulated by law. However, the "CFAI Interior Designer" title issued by the French Council of Interior Architects guarantees a recognized level of competence and the obligation to take out 10-year insurance.
What are the missions of an architect?
Overall design and building permit
The architect intervenes on the entire life cycle of a building, from initial sketch to final delivery. Their main mission is to design new constructions or extensions while respecting the technical, regulatory and aesthetic constraints of the site.
Their intervention becomes mandatory when a building permit concerns a floor area greater than 150 m², in accordance with Decree No. 2016-1738 of December 14, 2016. Only an architect registered with the Order can then sign the planning permission application.
Project management and responsibilities
Beyond design, the architect frequently ensures complete project management: coordination of technical design offices, contractor consultation, site supervision and work handover. Their responsibility is engaged on the solidity of the structure and its compliance with current standards.
The architect is subject to strict ethical obligations defined by the Code of Professional Duties. They must mandatorily take out professional liability insurance and a 10-year warranty covering defects for 10 years after handover.
What are the missions of an interior designer?
Transformation and optimization of existing spaces
The interior designer excels in restructuring and designing interior spaces. Their expertise covers room layout, volume optimization, material selection, lighting and furniture selection. They transform a poorly arranged apartment into a functional and harmonious living space.
Unlike architects, they do not work on the building's load-bearing structure or exterior facades. However, they can modify non-load-bearing partitions, create interior openings or completely rethink room distribution. For work affecting structural elements, they collaborate with a structural engineering firm.
Site supervision and contractor coordination
The interior designer generally offers a complete mission including site supervision. They coordinate the various trades (plumber, electrician, carpenter, painter), check work compliance and ensure respect for schedule and budget.
A CFAI-certified interior designer is required to take out professional liability and 10-year warranty insurance, thus offering their clients the same legal guarantees as an architect for work within their scope of intervention.
When to hire one or the other?
Cases where an architect is essential
Certain projects require the intervention of an architect registered with the Order. This is the case when your project involves:
- A building permit for floor area exceeding 150 m² after work
- Modification of the building's load-bearing structure (load-bearing walls, floors, framework)
- A change of use with facade modification beyond 150 m²
- New construction exceeding the regulatory threshold
Cases where an interior designer is the right choice
For interior renovation projects without major structural modification, an interior designer is often the most relevant choice. Their expertise is particularly suited to:
- Apartment renovation with room redistribution
- Optimization of poorly arranged spaces
- Creating atmospheres and choosing materials
- Site supervision for finishing work
Comparison Table: Architect vs Interior Designer
| Criteria | Licensed Architect | Interior Designer |
|---|---|---|
| Training | 6 years minimum (Master's + HMONP) | 4-5 years (Bachelor's/Master's) |
| Protected title | Yes (Order of Architects) | Not mandatory (CFAI recommended) |
| Building permit +150 m² | Authorized to sign | Not authorized |
| Load-bearing structure work | Yes | No (except with engineer) |
| Facade modification | Yes | No |
| Interior layout | Yes | Yes (specialty) |
| Moving non-load-bearing partitions | Yes | Yes |
| 10-year warranty | Mandatory | Mandatory (if CFAI) |
| Average fees | 8-15% of project budget | 10-15% of project budget |
How to choose the right professional for your project in Paris?
Faced with the complexity of Parisian renovation projects – constraints of Haussmann buildings, condominiums, strict regulations – surrounding yourself with the right professional is decisive for the success of your project. The choice between architect and interior designer depends above all on the nature of the work planned.
For apartment renovation without extension or facade modification, the interior designer offers targeted expertise and personalized support. Their in-depth knowledge of materials, layouts and constraints specific to Parisian apartments makes them the ideal partner to transform your interior.
Hauss Paris supports individuals and professionals in their interior design projects in Paris. As a specialized intermediary, we facilitate the meeting between your project and an interior designer suited to your needs, style and way of working. Renovation of Parisian apartments, volume optimization, office or commercial space design: from studio to large Haussmann apartment, we help you move forward with confidence through a human and structured approach.
FAQ: Your questions about architects and interior designers
Can an interior designer submit a building permit?
An interior designer can submit a building permit only if the total floor area after work remains below 150 m². Beyond this threshold, only an architect registered with the Order is authorized to sign the application. For interior design work not modifying the building's exterior appearance, no permit is generally required, regardless of surface area.
What is the fee of an architect compared to an interior designer?
Fees are comparable: between 8 and 15% of the project cost for a complete mission (design + site supervision). Architects tend to be at the lower end for high-value new construction projects, while interior designers apply similar rates for renovations. Some also offer packages or hourly rates (€80-200/h) for one-off services.
Can you hire both professionals on the same project?
Yes, it's even common for complex projects combining extension and interior renovation. The architect designs the extension or structural modifications and submits the building permit, while the interior designer handles the interior layout and decoration. This collaboration allows you to benefit from the specific expertise of each.
How to verify an interior designer's qualifications?
Check the CFAI directory at cfai.fr to verify if the professional is certified. Systematically request an up-to-date certificate of professional liability and 10-year warranty insurance. A CFAI interior designer has a professional card renewed annually after verification of their qualifications and insurance.
Sources: Order of Architects, French Council of Interior Architects (CFAI), Decree No. 2016-1738 of December 14, 2016