What a Zürich period building hides before you open the first wall
In short
An interior designer Zurich plans and coordinates the layout of a space — floor plan, light, materials, ergonomics — from the first sketch to site handover. In Zürich, fees run between 15 and 22 % of the works cost for a renovation, or 120 to 300 francs an hour. The local twist is the dense Gründerzeit period stock, along with the core zones (Kernzonen) and the ISOS inventory, which set what you may change inside — sometimes before style is even discussed.
You have bought a flat in a Gründerzeit building in Kreis 4, or you dream of opening the kitchen onto the living room in a hundred-year-old block. Then comes the question that stops everyone: who do you call, for what, and at what price? Between the professional who draws plans, the one who picks the light fittings and the one who touches the structure, the line is blurred. And in this city there is an extra layer owners often underestimate: a large share of the building stock is under some form of oversight.
Interior designer, decorator, architect: who does what
The three trades are constantly confused. The interior decorator works on the appearance of an existing space — colours, furniture, textiles, lighting — without touching its structure or layout, and needs no recognised diploma to practise. The interior architect designs the space itself: layout, circulation, light, ergonomics, bespoke joinery, and coordinates the trades. The architect in the strict sense (ETH training, SIA member) answers for the envelope, the load-bearing structure and the shell. For a Zürich flat renovation, the interior architect usually leads — you bring in the architect the moment load-bearing walls or the façade are touched.
- Rethinks the plan: walls, openings, circulation, integrated storage
- Produces plans, the specification and the materials concept, coordinates the firms
- Trained at a university of applied sciences (HES-SO, ECAL, HEAD); may be a VSI.ASAI member
- Worth it as soon as the layout is touched or the renovation is deep
- Works on the existing: colours, textiles, lighting, furniture, staging
- Advises without changing structure or layout
- No diploma required to practise
- Worth it to refresh a space whose layout already works
- Responsible for envelope, structure and shell
- Signs large-scale permit applications
- Essential for work on a load-bearing wall or the façade
- Fee often calculated over a broader scope
What an interior designer Zurich actually delivers
A commission is not just a pretty 3D render. It unfolds in stages, and the essentials are decided long before the choice of materials. Understanding this sequence helps you know where you stand, and not to pay a deposit for a phase you thought was already done.
Precise measurement of the existing space, mapping of constraints (load-bearing walls, shafts, ceiling heights, stucco) and of what the zone and inventory allow.
Several layout scenarios, roughly costed, before any material is chosen — this is where most of the budget is decided.
Final plans, choice of materials and a precise schedule serving as the basis for genuinely comparable bids.
Where needed, assembling and filing the building application, coordinating with the Kreisarchitektur and heritage conservation.
Firms compete on the same specification, bids are analysed, the recommendation is reasoned.
Coordinating the trades, controlling schedule and budget, quality assurance through to site handover.
Fees: what it costs in Zürich
Since 2020 the SIA fee scale is no longer binding: fees are negotiated. In practice, for a full renovation commission they run between 15 and 22 % of the works cost, and rather between 12 and 18 % for new build. On an hourly basis, count on 120 to 300 francs, depending on the firm's profile and the project's complexity. Zürich is among the most expensive places to build in Switzerland — which does not inflate the fee, but the works cost it is based on; hence the importance of a 10 to 20 % reserve.
Interior architecture fees — orders of magnitude
- By percentage: the fee tracks the works cost — transparent, but worth capping so it does not grow with the budget
- By the hour (120 to 300 francs): suited to advisory mandates or small scopes
- Fixed fee: possible on a well-defined scope, locks the amount in advance
- Always check: whether site management is included or not — that changes everything
An order of magnitude only holds once it is measured against your flat, your building and its position in the zone and the inventory. Compare architects in your canton
The Zürich factor: old stock, core zones and ISOS
This is the twist that surprises Zürich owners most. A large part of the housing stock dates from the Gründerzeit — stucco ceilings, box windows, parquet, generous ceiling heights — and a large part of the urban territory is overlaid with protection instruments. According to our research, roughly three quarters of Zürich's settlement area is captured by ISOS, the federal inventory of built sites worth protecting; its case-by-case application tightens above all where there is a direct effect on the townscape. Check the specific data for your address — these figures evolve and do not apply uniformly.
In the city's core zones, even smaller projects can become subject to a permit where they would be exempt elsewhere — integration into the townscape is assessed.
If the building is inventoried or protected, the conversion happens in agreement with municipal and cantonal conservation; the building advice is free and worth seeking early.
This federal inventory acts mainly through cantonal and municipal implementation; it can restrict work on façade, windows and roof, more rarely purely interior measures.
For any building predating 1991, an asbestos survey is required before demolition — Zürich's period and post-war buildings are regularly concerned.
Building permit: when you need one
Not every interior conversion needs a permit application. Purely interior renovations that touch neither the structure, nor fire protection, nor the use, nor the envelope are often permit-free in Zürich — removing a non-load-bearing partition between living rooms, for instance, is generally free. But as soon as a load-bearing wall, a fire-compartment element, the façade or the use comes into play, the assessment tips into permit territory. When in doubt, the city's Kreisarchitektur gives a non-binding first estimate — which is exactly what a locally experienced interior architect checks at the preliminary-design stage.
- Removing non-load-bearing partitions or changing openings in them
- Redoing floors, finishes, kitchen and bathroom within the existing plan
- Interior painting, built-in cupboards, lighting and fittings
- Maintenance with no impact on structure, use or envelope
- Work on a load-bearing wall or the structure
- Change of use (for example office to housing)
- Work on façade, windows, roof or envelope
- Project in a core zone, ISOS perimeter or on a protected object
Ordinary permit procedures generally take several months; on a protected object, review by heritage conservation is added. A professional builds these lead times into the schedule from the outset, rather than meeting them later as a delay.
Condominium ownership: the consent no one thinks of
In a condominium flat, load-bearing walls, the façade, the roof and the stairwell are part of the common elements — even where they sit inside your home. Work on those elements requires the consent of the owners' community, and value-adding (useful) measures generally require a qualified majority. Building without a resolution risks being ordered to restore the original state. Clarify the by-laws and the required consent before you design — not once the tradespeople are booked.
You recognise a good interior project by what you do not see: the square metres gained, the fluid circulation, the storage you no longer notice because it simply fits.
When to commission and how to choose
The best time to call an interior architect is before purchase, and in any case before the first request for a quote. On the plan, moving a bathroom costs a pencil stroke; on site, it costs weeks and several thousand francs. Involving the professional early also means not buying a property whose zone, protection status or by-laws forbid precisely what you had in mind.
- Is the professional a university-of-applied-sciences graduate or a member of VSI.ASAI (the Swiss association of interior architects)?
- Can they show comparable sites completed in Zürich's old stock?
- How are the fees set — percentage, hourly or fixed — and what exactly do they cover?
- Is site management included, or does the commission end at plan handover?
- Do they know the Zürich procedures: Kreisarchitektur, heritage conservation, core zone and the pre-1991 asbestos survey?
Common mistakes in Zürich
Discovering the core zone, ISOS or heritage protection after purchase means starting the project from scratch.
In a condominium, work on common elements without a resolution can lead to a restoration order.
Without a common specification, two bids for the same flat can differ twofold without either being « wrong ».
Most renovations overshoot the budget by 15 to 25 % because of what appears once the walls are opened; plan a 10 to 20 % reserve.
A project in Zürich?
Describe your property and your intention — you get a first read on feasibility, layout and order of magnitude, before any commitment.
Describe my projectFAQ
The interior architect designs the space itself — layout, walls, circulation, light, ergonomics — and coordinates the firms; they are trained at a university of applied sciences (HES-SO, ECAL, HEAD). The decorator works on the appearance of an existing space (colours, furniture, textiles) without changing its structure, and needs no recognised diploma. For a renovation that touches the layout, you need the interior architect.
For a full renovation commission, fees generally run between 15 and 22 % of the works cost, and between 12 and 18 % for new build. On an hourly basis, count on 120 to 300 francs. As the SIA scale has not been binding since 2020, these amounts are negotiated; since Zürich is among the most expensive places to build in Switzerland, a budget reserve of 10 to 20 % is especially important.
Purely interior renovations with no impact on structure, fire protection, use or envelope are often permit-free; removing a non-load-bearing partition is generally free. As soon as a load-bearing wall, the façade, the use or a protected object is concerned, the project needs a permit. When in doubt, the city's Kreisarchitektur gives a non-binding first estimate.
In core zones, even smaller projects can require a permit because integration into the townscape is assessed. ISOS is a federal inventory of built sites worth protecting that covers roughly three quarters of Zürich's settlement area and mainly concerns façade, windows and roof, more rarely purely interior measures. The address-specific data should be checked before purchase or design.
As early as possible — ideally before purchase and in any case before requesting a quote. The most expensive decisions (layout, openings, moving wet rooms) are made on paper; changing them mid-site costs weeks and several thousand francs. Early involvement also lets you clarify the zone, the protection status and, in a condominium, the community's required consent.