Two fee proposals, one double the other, for the same apartment: what the amount doesn't tell you

Two firms visit the same 100 m² apartment, listen to the same project, ask roughly the same questions — and hand in two proposals: one at CHF 9,500, the other at CHF 19,000. The natural reflex is to conclude that the second is overcharging, or that the first has forgotten something. In the vast majority of cases, neither: the two amounts simply don't pay for the same work. And that is precisely what the total, read on its own, will never tell you.

Three fee models, three different logics

The flat fee sets a total amount agreed before the mandate begins. It works well when the mission is precisely delimited: layout advice, a layout plan, a colour-and-materials concept for one or two rooms. For this kind of one-off intervention, a flat fee of between CHF 2,000 and CHF 5,000 is common on the Swiss market. Its limit is mechanical: as soon as the scope moves — one more room, an extra variant to study — the flat fee no longer covers it, and every addition is negotiated as an amendment.

The hourly rate bills the time actually spent, generally between CHF 120 and CHF 300 per hour depending on the region, experience and the structure of the firm — a self-employed architect starting out and an established firm with staff don't carry the same overheads. It's the most honest model for short missions or those whose scale nobody can estimate at the outset: support during an ongoing site, taking over a project started by someone else, a feasibility study in a building full of unknowns. Its trade-off is well known: without a cap agreed in writing, the total remains open.

The percentage of the cost of works, inherited from the SIA method, ties the fees to the real scale of the project. For an interior architect's full-design mandate — from first sketch to site supervision — practice generally sits between 8 and 12% of the works budget. It's the standard model for the full mandate: it pays for work that genuinely grows with the project. It does, however, assume a works budget defined from the outset, and it raises a question worth asking frankly before signing: what happens to the fees if the cost of works rises along the way?

How much an interior architect costs in Switzerland, project by project

Brought back to concrete projects, the full-design mandate — the most common case when you engage an interior architect for a renovation — gives the following orders of magnitude. These amounts cover the design, the tendering to contractors and the site supervision; they come on top of the works budget, and are generally understood excluding VAT at 8.1%.

Two corrections to this rule of three. At the lower end, the percentage quickly hits its limit: designing a CHF 40,000 renovation doesn't take five times less work than a CHF 200,000 one, and many firms apply a minimum amount or switch to a flat fee for small projects. At the upper end, the percentage tends on the contrary to become degressive on large budgets. Finally, a point almost nobody spells out when announcing "a budget of CHF 150,000": that figure generally refers to the works alone — the fees come on top, not out of it.

Why there is no longer an official tariff

The reference framework for architecture mandates in Switzerland remains the SIA 102 regulation ("Regulation concerning services and fees of architects"), in its 2020 edition. It's a private regulation: it only applies if the contract explicitly refers to it, and interior architects draw on it without being bound by it. Its value for the client isn't to impose a price, but to break the mission down into precise phases — which makes it possible to know exactly what is being ordered, and to commission only part of the project.

Because on the price itself, everything has changed. For decades, the SIA published a method that calculated fees from the cost of the building, with coefficients updated every year; the KBOB, the Confederation's procurement body, published recommended hourly rates of its own. Under pressure from the Swiss Competition Commission (COMCO), which saw these scales as horizontal price-fixing, the KBOB abrogated its recommendations in 2017, and the 2020 edition of the SIA 102 regulation removed the calculation based on the cost of the building. The direct consequence: there is no official tariff today, fees are freely negotiated, and the ranges cited in this article describe practices observed on the market — not an enforceable scale.

The SIA phases, translated into concrete work

The breakdown into phases is the part of the SIA 102 regulation most useful to the client, because it turns an abstract amount into a list of deliverables. A full mandate moves through the following stages, in order — and each can be commissioned or not.

• Preliminary design: analysis of the existing condition, feasibility, first layout variants and a rough cost estimate — the phase where the big decisions are made
• Detailed design: definitive plans, choice of materials and equipment, a detailed item-by-item cost estimate
• Permit procedure, if the works require it: assembling and filing the application with the municipality
• Tendering: a brief for the contractors, competitive bidding, analysis of the quotes and award of the contracts — the phase that makes quotes genuinely comparable
• Execution and site supervision: coordinating the tradespeople, monitoring quality and costs, managing the unexpected, handover of the works

The way the cost splits across these phases often comes as a surprise: the design work (preliminary and detailed design) generally accounts for around a third of the total fees, the tendering for around a tenth, and the realisation phases — execution drawings and site supervision — for roughly half. In other words, a mandate that stops at the plans costs roughly half as much as a full mandate. That is the first explanation, and by far the most frequent, for a seemingly inexplicable gap between two proposals.

Included in the fees, or billed on top

Even with identical phases, two proposals can hide different scopes. The fees cover the architect's intellectual work; around them orbit ancillary costs — disbursements, third-party services — whose treatment varies from one firm to another: some build them into the flat fee, others bill them on top at cost or with a flat surcharge of a few percent. A serious fee proposal settles these points in writing, before signature.

Why two honest proposals vary by a factor of two

The ranges circulating online seem to contradict each other: 8 to 12% here, 15 to 22% there. They don't measure the same thing. The top of the range — 15 to 22% of the cost of works — corresponds to the full mandate of an architecture firm on a renovation, all SIA phases included: detailed execution drawings, the permit file, construction management in the full sense, on sites where the share of technical risk is high and the works budget often modest relative to the coordination work. An interior architect's full-design mandate, at 8-12%, covers a tighter scope: the interior layout, its materials, its tendering and site supervision focused on the interior fit-out — with no structural work and no overall construction management. Two proposals for "the same" project can therefore legitimately differ by a factor of two, if one stops at the plans and the other carries the project through to handover.

The rest of the gap comes down to more familiar factors. Experience, first: a recognised, in-demand firm bills at the top of the ranges — and in exchange brings a contact book of proven tradespeople and sites that go off the rails less often. Structure, next: a self-employed architect without office overheads can offer hourly rates markedly below those of an agency with staff, for a service that can be equivalent on a simple project. Region, finally: in the economic centres — Geneva, Lausanne, Zurich, Basel, Zug — the going rates sit structurally at the top of the ranges, as for every building trade.

What an interior architect really saves you

The question deserves an honest answer, without the "they pay for themselves" slogan that no serious professional can guarantee. The real savings come through three identifiable mechanisms. The first is the framed tender: contractors pricing against the same detailed brief hand in comparable quotes, which avoids unknowingly choosing the least complete offer — the mistake that costs the most in site extras. The second is sequencing: deciding the lighting before the walls are closed up, ordering the bespoke pieces before the site ends, choosing the finishes together rather than in isolation — each of these ordering mistakes, caught in time, saves rework that runs into thousands of francs. The third is knowledge of prices: a professional who sees dozens of quotes a year spots an overpriced item or a suspicious omission in minutes.

And there are cases where the mandate simply isn't justified. For a like-for-like replacement — a kitchen installed in the same spot, a bathroom refreshed without touching the layout — the fees are a net extra cost that no saving will offset. The mandate makes sense when the project involves trade-offs: a layout to rethink, several tradespeople to coordinate in an older building, a tight budget to spread across competing items. It's on those projects that fees of 8 to 12% are partly recouped — never guaranteed, often observed — through better-negotiated quotes and avoided mistakes.

Fees aren't judged in the absolute, but against what they replace: dozens of hours of coordination, and decisions made in the right order instead of being corrected after the fact.

Comparing two fee proposals without getting it wrong

• Bring both proposals back to the same phases: if one includes site supervision and the other doesn't, comparing the totals is meaningless
• Count the deliverables: number of layout variants, plans, visuals, meetings — that's where the real differences in service hide
• Add up the announced ancillary costs (travel, 3D renders, prints) to compare full costs, not bare fees
• Ask each firm what triggers an amendment: a firm that answers this question precisely is used to well-framed mandates
• Check two or three references from comparable projects, as you would for a contractor — the lowest amount is only a good deal if the service follows
• Be wary of a proposal markedly below the others: as with contractors' quotes, it almost always hides a reduced scope or revisions counted to the bare minimum