Interior designer fees in 2026: how to set them, present them and get them accepted

The three fee models, and when to use each

1. A percentage of the cost of the works

The benchmark model for full-service assignments. It aligns your fees with the real scale of the project and naturally absorbs changes in scope. In practice, the rate goes down as the works budget goes up: a higher rate on a small, demanding project, a lower rate on a large budget.

Its constraint: it requires a credible cost estimate from the concept stage, that's the whole point of our cost-estimation method, and flawless transparency, because clients quickly realize that your fees grow with the budget.

2. A flat fee per assignment

Ideal for assignments with a clearly defined scope: a space-planning study, concept and mood boards, a drawing package, a furniture shopping list. The client knows what they're paying for, and you know what you're delivering. The golden rule: spell out exactly which deliverables are included and how many rounds of revisions, it's the absence of that limit that turns flat fees into money pits.

3. Hourly rate or time-based billing

For one-off advice: an advisory visit, shopping guidance, a second opinion on contractors' quotes. It's also the contractual safety net for anything outside the scope of the other two models ("any work beyond the assignment will be billed at a rate of…").

These ranges are indicative: your positioning, your location and your order book remain the primary factors. The mistake isn't being above or below the market, it's not being able to justify where you stand.

A worked example: what does a 100 m² house cost?

Take the most common case in 2026: renovating a 100 m² house. Depending on the scope entrusted to you, the orders of magnitude have nothing in common — and that's precisely what you need to show the client at the very first meeting.

• Layout study alone (survey, layout plans, mood boards): observed flat fees run from €1,500 to €2,500 depending on the region, i.e. €15 to €25/m². The top of the range applies in Paris and its inner suburbs, the bottom in regional markets where day rates are gentler.
• Full design (concept → tender documents) on a works budget of €80,000 excl. VAT: 5 to 8%, i.e. €4,000 to €6,400, often presented as a flat fee per phase.
• Full-service assignment (design + contractor consultation + site supervision) on the same budget: 10 to 12% in practice for a project this size, i.e. €8,000 to €9,600, billed per approved phase.

The same project therefore goes from €1,500 to nearly €10,000 in fees depending on the assignment. Hence the rule: never announce a figure before the scope is framed — the scope sets the price, not the floor area. And for the percentage to hold, you need a credible works budget from day one: that's what a trade-by-trade estimate is for.

Percentage or flat fee: how do you decide?

The two models don't pay for the same thing. The percentage pays for a commitment on a project whose scale can move: it follows the works budget, absorbs scope extensions naturally, but assumes total transparency on the estimate. The flat fee pays for a defined deliverable: it reassures the client on small scopes, but becomes dangerous as soon as the project can grow, since every "extra" request has to be renegotiated cold.

• Stable scope and closed deliverables (study, plans, mood board) → flat fee, with the number of revision rounds in writing.
• Works budget beyond €30–40k, or an assignment including the works phase → percentage, with milestones per approved phase.
• Hybrid assignment → mix the two: a flat fee on design, a percentage on consultation and supervision. Perfectly defensible in the contract, provided it's written down.

If you're starting out, resist the temptation of the underpriced "do-everything" flat fee to land the job: it's the number-one mistake of the first years, and one of the five late discoveries we detail in our guide from degree to first job site.

Presenting your fees: clarity does half the work

Most difficult fee negotiations aren't about the amount, they're about vagueness. Three rules defuse them:

• A fee quote separate from the works budget. Mixing the two makes your fees look like an "add-on" to the project instead of part of it.
• A breakdown by phase, concept, detailed design, contractor consultation, on-site supervision, with each phase's deliverable spelled out in black and white.
• Billing milestones tied to approvals, not to the calendar: each approved phase triggers its invoice. The client pays for what they've seen and signed off on.

Getting accepted: show the value before the price

A client doesn't buy a percentage, they buy an outcome: a project under control, a budget that holds, a result that lives up to expectations. So your fees are won before the price page: through the method you demonstrate (site survey, trade-by-trade estimating, scheduling), through the references you show, and through the tools the client sees, a real-time client portal where they approve every quote online says "professional" louder than any sales pitch.

Remind them, too, of what your clients already read in our guides: fees of 8 to 15% are often offset by the savings a professional generates on site, mistakes avoided, deadlines met, contractors' quotes negotiated down.

Frequently asked questions