Renovating in Switzerland: the two quotes you can't compare
In short
For a renovation in Switzerland, the interior designer vs general contractor decision determines who designs, who coordinates and who carries the risk. The interior architect bills a fee of 15 to 22 % of the works (or 120 to 300 CHF/hour) and defends your interests against the trades. The general contractor delivers a turnkey lump-sum price with a coordination margin baked in, often estimated at 10 to 20 %. This article compares both models, their pricing logic and the cases where each one makes sense.
You have two offers on the table to renovate your apartment. The first runs to three pages and details a fee calculated as a percentage. The second announces a single figure, a lump sum, all included. At first glance the second looks simpler and safer. In reality, the two documents describe neither the same profession, nor the same split of risk, nor the same outcome on your site.
Choosing your main point of contact is the first decision of a renovation, before the first blow of the hammer. It shapes who designs your spaces, who negotiates with the trades, who checks the quality and who calls you when a wall hides a nasty surprise. Here is how the two models actually work, and what they cost you.
Two ways to run a project
The interior architect is a designer and an agent. He works for you, defines the project, draws the plans, writes the tenders and then steers the trades you hire directly. His interest is aligned with yours: to get the best value for money from the firms, because he is not selling their work.
The general contractor (GC) is a single-source builder. He sells you a finished work at an agreed price, then subcontracts all the trades himself. You sign one contract, with one party responsible for the result. In exchange, the firm's margin and its view of the project are baked into the lump sum.
Interior designer vs general contractor: who does what
The fundamental difference lies in where each one sits in the chain. One is your adviser, paid to defend your project; the other is your supplier, paid to deliver a product. Neither good nor bad in itself: two logics that serve different needs.
- Bespoke design and a strong aesthetic stance: this is the core of the interior architect's craft.
- Guaranteed price and a single deadline: this is the general contractor's commercial promise.
- Negotiating the offers in your interest: only possible when the agent is not selling the works.
- A single point of contact when something is defective: this is structurally the general contractor's advantage.
- Independent agent, aligned with your interests
- Transparent fee: 15 to 22 % of the works or 120 to 300 CHF/hour
- You keep the choice and the contract of each tradesperson
- Strong design, tailored to the existing fabric and heritage
- You coordinate several contracts (with his support)
- Ideal for bespoke projects, unusual spaces, older buildings
- Provider who sells the work and subcontracts the trades
- Lump-sum price, coordination margin baked in (~10 to 20 %)
- One contract, one party responsible for the result
- Often standardised design to hold the price
- A single point of contact from start to finish
- Ideal for standard projects, tight schedules, capped budgets
How the price is really built
The interior architect bills a service. For a renovation, the fee usually sits between 15 and 22 % of the value of the works, a higher rate than for new build because the existing fabric holds more unknowns. Small jobs are often billed by time, in the order of 120 to 300 CHF an hour. Since 2020, following an intervention by the Competition Commission, the calculation formula of the SIA fee scale has been withdrawn: fees are now freely negotiated.
The general contractor, by contrast, bills no visible fee. He wraps his pay inside the lump-sum price, as a coordination and risk margin. Public estimates put this add-on in a wide range, often cited at around 10 to 20 % above the cost of the trades; the exact figure is rarely broken down on the quote. So it is not free: you are paying for the price guarantee and the comfort of a single contract.
What each model takes off your project
Be careful not to conclude too quickly that the general contractor is cheaper because his margin looks lower. The architect's fee percentage applies to works he negotiated for you, often at a better price. The GC's margin is added to costs he controls alone. Two different calculation bases, which make a direct comparison of the percentages alone meaningless.
Torn between the two quotes on your table? A first conversation often clarifies which one matches your project, your budget and your appetite for risk. Compare architects in your canton
Who carries the site risk
This is the most misunderstood point. With a general contractor, the risk of execution and overrun is transferred to the provider: if a subcontractor goes bankrupt or a line item spirals, it is the GC who absorbs it, within the limits of the contract. With an interior architect under direct client management, you contract each tradesperson yourself, so you carry the financial risk of the unforeseen, with the architect advising you and defending your rights.
A « turnkey » price often excludes items: permits, taxes, external works, options. Read the list of exclusions before you sign.
In renovation, overruns commonly reach 15 to 25 %. Keep 10 to 20 % of the budget aside, whichever model you choose.
Who steps in if a defect appears two years later? Have the warranty period and the responsible contact set down in writing.
An architect's quote details the works; a GC lump sum hides them. Ask for the same level of detail to compare honestly.
The real price of a renovation is not found in the lowest quote, but in the one that most honestly describes what is going to happen.
One contact or several
The general contractor sells simplicity first: one contract, one figure, one responsible party. For a busy client or one unfamiliar with construction, that comfort has real value. The downside is the loss of control: you do not choose the trades, you do not see the price breakdown, and any change goes through a renegotiation of the lump sum. With an interior architect you multiply the contracts but you keep your hand on every decision, every material, every firm.
Quality and older buildings: the hidden stake
On a recent, standard building with a clear specification, the general contractor works well. The stake shifts as soon as you touch delicate existing fabric: an apartment with character, an older building, a protected element, an unusual space. There, the standardisation that lets the GC hold his price becomes a handicap. The interior architect, whose whole craft is to adapt the project to the place, protects the heritage value and the coherence of the result.
When to choose one or the other
There is no universal answer, but situations that clearly lean one way. The right reflex is to start from your project, your budget and your availability, not from a matter of principle.
- Bespoke project, older or characterful building, strong aesthetic requirement: the interior architect.
- Standard renovation, tight schedule, a wish for a single point of contact: the general contractor.
- Capped budget needing a guaranteed price from the outset: the general contractor.
- A will to control every choice and negotiate every line item: the interior architect.
- A hybrid solution: an interior architect for the design, then a GC for the supervised execution.
Let's talk about your renovation
AC Design designs and steers bespoke renovations in Switzerland. We help you choose the right model and compare quotes at their true value. Get in touch for a first, no-obligation conversation.
Describe my projectFAQ
Neither is systematically cheaper. The interior architect bills 15 to 22 % of works he often negotiates at a better price for you. The general contractor bakes in an estimated margin of 10 to 20 %, but on costs he controls alone. Comparing the percentages alone is misleading: you have to look at the final price for the same scope.
It is a billing method where the architect's fee equals a percentage of the value of the works. It is neither mandatory nor regulated: since 2020 the SIA fee-scale formula has been withdrawn after an intervention by the Competition Commission. Fees are freely negotiated, by percentage, lump sum or time.
It covers the work described in the contract, at a price fixed in advance. But a « turnkey » lump sum frequently excludes items: permits, taxes, external works, finishing options. Always read the list of exclusions and have the exact scope set down before you sign.
Count on 10 to 20 % of the budget as a reserve for the unforeseen. Renovations commonly overrun their initial budget by 15 to 25 %, especially in older buildings where opening up walls sometimes reveals surprises. This reserve is useful whichever model you choose.
Yes, it is in fact a common solution. The interior architect handles the design, the plans and the defence of your interests, then a general contractor executes the works under his control. You keep the design quality while enjoying a single point of contact for the build.