In short
- A decorator works on the look and feel of an existing space: colours, materials, furniture, lighting.
- An interior architect transforms the space itself: room layout, volumes, light, electrics, plumbing and materials.
- For a complete renovation, they are the first professional to call.
- A decorator does not coordinate contractors or oversee the building work.
- In France, the title is not regulated: only the designation “architecte d’intérieur CFAI” is protected.
- As soon as they design or oversee building work, this professional must hold ten-year liability insurance (assurance décennale).
- A registered architect (inscrit à l’Ordre des architectes) is only mandatory when a building permit takes the total floor area above 150 m², which mainly concerns extensions or adding a storey to a detached house. At first glance, the two professions look alike. They share a vocabulary, a design culture and an eye for light and materials. Their scope, however, has almost nothing in common.
So the real question is not who has the better taste. It is who draws the new layout, who checks that it can actually be built, and who manages the contractors.
Differences between an interior architect and a decorator: it all starts with scope
A decorator dresses an existing room
An interior decorator works on what you can see and touch: colour palette, wallpaper, furniture, freestanding lamps, curtains, rugs and accessories. Their work focuses on the atmosphere of a space whose layout stays exactly as it is.
They listen to their clients’ tastes and preferences. A decorator puts together mood boards (collages of images, colours and samples), selects furniture and sometimes helps with purchasing. They do not reconfigure rooms, draw electrical plans or request quotes from contractors. When building work is needed, they refer clients to other professionals.
To furnish a new-build flat or warm up a living room that already works well, a decorator is often all you need. Just don’t expect any building work if you hire one.
An interior architect redesigns the space
Their role begins with reading the place and the people who live in it: who lives there, at what times of day, with what light, and what storage they need. They analyse the space, its volumes, how people move through it and the constraints of the building, then propose a new layout.
Their design work covers how the rooms are arranged, where the kitchen and bathrooms go, the electrics and plumbing, built-in lighting, acoustics and built-in storage. They set it all out in technical drawings, cross-sections and 3D visuals, so that every decision is made before the first hammer swings.
They can also take on full project management(maîtrise d’œuvre), meaning they run the building work on the client’s behalf. In practice, they have contractors price the same set of tender documents, coordinate the tradespeople and monitor progress right through to handover. Handover is the final inspection, where you check together that everything has been done as specified. Decoration then comes last, as the finishing touch to the project.
What about a DPLG or HMONP architect?
A third professional often comes into the comparison: the registered architect, listed with the French Order of Architects (Ordre des architectes). DPLG refers to the former qualification, awarded until 2007. HMONP is the licence that now allows an architect to practise under their own name. The title is protected by the French law of 3 January 1977. Their core territory is new builds, extensions, façades and roofs.
To transform the interior of a flat or house without extending it, you are not required to hire one. It becomes mandatory for a private individual when a building permit takes the total floor area (surface de plancher) above 150 m². Put simply, floor area means the enclosed, covered space with a ceiling height of more than 1.80 m.
For changes that only require a simple prior declaration to the town hall (déclaration préalable), such as replacing windows, an architect is never required.
One point to watch for properties held through a French property company (société civile immobilière, or SCI): a company must hire an architect whenever a building permit is required, whatever the floor area.
An interior architect, on the other hand, specialises in transforming existing spaces. That is exactly what a complete renovation calls for.
Roles compared: who does what?
| Task | Decorator | Interior architect |
| Colours, materials, furniture, lighting | Yes | Yes |
| New room layout, partition walls added or removed | No | Yes |
| Electrical, plumbing and lighting plans | No | Yes |
| Bespoke furniture designed alongside the layout | Rarely | Yes |
| Tender documents describing the work, for contractors to price | No | Yes, with full project management |
| Coordination of the different trades | No | Yes, with full project management |
| Site supervision and final inspection | No | Yes, with full project management |
| Opening up a load-bearing wall | No | Designs it, with a structural engineer |
| Ten-year liability insurance (décennale) | No, it is not part of their job | Yes, it is mandatory |
In short: a decorator only works on the first row of the table, the one covering colours, materials and furniture. Everything else in the project happens before the decoration stage and falls outside their remit.
Training and qualifications: two professions, two paths
Five years of study for a qualification
Interior architecture takes five years to learn, at a school specialising in interior architecture and design. This can be a public school of applied arts, a university programme or an accredited private school.
The training combines:
- drawing and spatial design
- building techniques
- regulations (fire safety, accessibility)
- light and materials
- project organisation and site supervision
Experience does the rest: this profession is learned as much on building sites as in the classroom.
A point that is often overlooked: in France, the title is not protected. Nothing prevents someone with no qualifications or proven skills from using it. Training and recognition by peers therefore become the real criteria for choosing.
A profession open to all, with no qualification required
Interior decoration requires no formal qualification. Backgrounds vary widely:
- a BTS in interior fit-out design (Étude et réalisation d’agencement), a two-year higher education diploma
- a DNA in design (diplôme national d’art), the national art degree awarded by fine arts schools after three
- years of higher education
- private courses, in person or online
- or simply experience in the industry
Some decorators have a real flair for composition. Their skills do not, however, extend to building techniques or coordinating tradespeople.
What the French Council of Interior Architects guarantees
The French Council of Interior Architects (Conseil français des architectes d’intérieur, CFAI) is the leading professional body for interior architecture in France. It awards the protected designation “architecte d’intérieur CFAI”, which requires one of the following two conditions:
- having studied at a school recognised by the CFAI and completed three years of professional practice
- having presented a portfolio of completed projects and passed an interview before a panel of professionals
In both cases, the professional commits to following a code of professional conduct and ethics. For a private client, it is the simplest way to check someone’s qualifications in an unregulated profession. Christophe Sarlandie, a CFAI-accredited interior architect, served as the council’s vice-president for several years.
In Switzerland, VSI-ASAI, the Swiss professional association for interior architects, offers a comparable benchmark. It is useful if you are looking for an interior architect in Geneva.
Liability and insurance: what people check too late
Ten-year liability insurance: who does it apply to?
The ten-year guarantee (garantie décennale) covers, for ten years, serious defects that compromise a building’s structural soundness or make it unfit for use. Since the Spinetta Act of 1978, any professional who can be held liable under this guarantee must be insured.
The French Civil Code (Article 1792-1) classes the following as “builders”:
- architects
- contractors
- technical specialists
- more broadly, anyone bound to the client by a contract to design or build a building or interior works
An interior architect who designs building work or oversees its execution falls within this scope. Ten-year liability insurance and professional indemnity insurance are then mandatory.
A decorator who sticks to aesthetic advice and choosing furniture is not affected, because they do not alter the building itself. Good practice: ask for an insurance certificate in the professional’s own name, valid on the date work starts on site, that clearly lists the activities they carry out. At Atelier Christophe Sarlandie, insurance is included in the interior architect’s fees and set out in every written proposal.
Load-bearing walls: who designs, who calculates, who approves?
You often read that this professional “doesn’t touch the building’s structure”. The reality is more nuanced.
They can design the opening of a load-bearing wall, or an opening in a floor to fit a staircase. They do not do the calculations themselves: a structural engineering firm checks and approves the solution. In a co-owned building (copropriété), load-bearing walls are generally part of the common areas, and opening one up must be approved by a vote at the co-owners’ general meeting.
This is the process followed to combine two flats in Lyon:
- precise measurements of the existing flat
- study with the structural engineer
- proposal presented to the co-owners, followed by a vote at the general meeting
- design of a 190 m² family home, created from a 95 m² flat and the flat next door
Ce type d’opération sort entièrement du champ de la décoration.
Rénovation complète : pourquoi faire appel à un architecte d’intérieur ?
Une rénovation complète ne se résume pas à une addition de pièces refaites. Elle engage l’organisation générale du logement, l’électricité, la plomberie, la lumière et le budget. Elle suppose aussi de coordonner une dizaine de corps de métier : maçon, plaquiste, électricien, plombier, menuisier, carreleur, parqueteur, peintre, cuisiniste.
Lire le potentiel d’un lieu
In the Haussmann-style flat on Rue Victor-Hugo, the kitchen was moved into the room next to the living room. That single change connected the living room, dining room and kitchen into more than 70 m² of living space. It also made it possible to put all the bedrooms on the quiet courtyard side. No sofa could have achieved that.
Furniture never fixes a poor layout.
Anticipating technical constraints from the very first drawings
In Lyon’s older buildings, constraints quickly come to light:
- timber floor structures
- uneven floors
- irregular walls
- ageing electrics and plumbing
- difficult site access on the Presqu’île or the slopes of the Croix-Rousse
Anticipating them on paper avoids improvised decisions along the way, which are costly and compromise the result. That is the whole point of the stages of a high-end complete renovation: comparing several options, refining every detail, then drawing up the tender documents so that every contractor prices exactly the same work.
Keeping to budget and schedule
The cost of a complete renovation in Lyon usually ranges from €1,500 to €2,000 per m², including VAT, as soon as rooms are reconfigured. At that level, a poorly compared quote or an overlooked interface between two contractors’ work can quickly add up to thousands of euros.
Under a project management contract, their role is to:
- compare quotes on a like-for-like basis
- draw up the schedule
- check the quality of workmanship
- carry out the final inspection with the client
When a decorator is enough
A decorator remains the right person to call when the layout works, the electrics and plumbing are recent, and all you want is to change the feel of a room without any building work. That might mean furnishing a new-build flat, furnishing a bedroom or making a living room feel warmer. Hiring an interior architect to choose cushions would make little sense.
Interior architecture and decoration: two roles that work hand in hand
Les deux approches ne s’opposent pas. Dans une rénovation complète, la décoration arrive en fin de parcours, une fois les volumes, la lumière et les matériaux arrêtés. Dans les projets que l’Atlier Christophe Sarlandie accompagne, elle se met en place après le départ des entreprises, quand plus rien ne bouge dans le plan.
When the same professional handles both, the decor naturally extends the design choices. In the elegant period flat on Boulevard des Belges, overlooking the Parc de la Tête d’Or, the furniture works in dialogue with what was preserved or newly created:
- furniture: a Togo sofa by Ligne Roset, a black marble table veined with white
- fixtures and finishes: the original fireplace, antique herringbone parquet flooring, and steel panels with a rust-coloured patina
Bespoke furniture (bookcases, walk-in wardrobes, built-in storage), on the other hand, clearly falls within interior architecture: it is designed at the same time as the layout.
How to choose your interior architect
Before signing, six points are worth checking.
- Training and accreditation. A degree in interior architecture, plus the CFAI designation in France or VSI-ASAI membership in Switzerland.
- Insurance. Up-to-date certificates for ten-year liability and professional indemnity insurance, in the professional’s own name.
- Comparable projects. The same type of property and scale of work, with floor areas and budgets stated.
- The exact scope of the assignment. Design only, or full project management through to the final inspection.
- A written contract. Stages, deliverables, fees and payment schedule, all in black and white.
- Your point of contact. Knowing who does the design and who actually comes on site.
Un premier rendez-vous sert à clarifier tout cela. À l’atelier, ce rendez-vous conseil de deux heures est facturé 190 € TTC. Il permet d’établir le cahier des charges du projet, autrement dit la liste précise de vos besoins, avant l’étude de conception.
Les erreurs fréquentes quand on hésite entre les deux
- Entrusting a major renovation to a decorator, then finding yourself dealing with the contractors alone.
- Starting with the decor. Mood boards and furniture chosen before the layout is finalised often have to be redone.
- Relying on the title “interior architect” alone, without checking training, professional accreditation and insurance.
- Bringing in multiple professionals (decor consultant, kitchen fitter, a builder who “does it all”) with no one to coordinate the whole project.
- Believing a registered architect is required to transform a flat, and delaying the work for no reason.
Deciding based on what will change in your home
If there is no building work involved, a decorator may be enough. As soon as you touch the room layout, the electrics, the plumbing, the walls or anything built into the fabric of the home, such as a bathroom vanity unit, a kitchen or a door, an interior architect becomes the natural choice, ideally with full project management.
Based in Lyon and Divonne-les-Bains, Atelier Christophe Sarlandie handles complete renovations of flats and houses, from design to site supervision. Whether you are looking for an interior architect in Lyon or an interior architect in the Pays de Gex, the approach is the same: a single point of contact from the first sketch to the final inspection, with decoration included if you wish.
To get a sense of your budget, the cost estimator gives you an initial price range. You can then discuss your project with the atelier.
FAQ: key takeaways
Interior architect or decorator: which should you choose for a complete renovation?
An interior architect. As soon as the layout, electrics or plumbing change and several contractors are involved, you are outside the scope of decoration. Whenever there is building work, they are the one with the expertise.
What training should you expect from an interior architect?
Five years of specialised training, ideally at a school recognised by the CFAI, and verifiable experience on properties comparable to yours.
Can you open up a load-bearing wall with an interior architect?
Yes. They design the opening to fit the overall project, an engineer does the calculations and, in a co-owned building, the co-owners’ general meeting must approve it.
Do you need a DPLG architect to renovate a flat?
No, unless a building permit takes the floor area above 150 m², for example for an extension or adding a storey to a house, or if the property belongs to a company (including an SCI) that applies for a permit.
Can an interior architect also take care of the decoration?
Yes. It comes at the end of the process, which ensures consistency between the volumes, materials and furnishings.
