Reworking an old-town flat in Basel without falling foul of heritage rules

A period flat in Kleinbasel, high ceilings, a stucco cornice, but a kitchen from the eighties and a layout that no longer convinces anyone. The first instinct is to tear out walls. In Basel that is exactly the moment when a project is either set up cleanly or turns expensive. Many of these buildings sit in a protected zone or on the inventory of buildings worth preserving, and what may be changed inside as well as outside is not the owner’s decision alone. A wrong first move, such as removing a period door or chiselling away stucco, can often only be corrected at great cost, if at all.

What this professional actually does

The role is often confused with decoration. In reality the work starts with structure and layout: where a wall can be opened, how daylight enters, which paths link the entrance, kitchen and bathroom. Only then come materials, lighting, built-in joinery and the coordination of trades on site.

Unlike the university-trained architect, the title is not protected in Switzerland. The professional body VSI/ASAI and training at HES-SO, ECAL or HEAD offer guidance. Anyone reworking a protected Basel property should also ask for references where the practice has already worked with the cantonal heritage office. Experience with permit procedures often weighs more on the outcome than design ambition alone.

When an interior designer Basel is genuinely worth it

Not every coat of paint needs specialist planning. But as soon as the layout changes, a bathroom moves or protected fabric is touched, the risk of costly decisions drops sharply. Typical triggers for a mandate are:

• A period flat or town house in the old town of Grossbasel or Kleinbasel undergoing structural change
• A property in a protected or conservation zone where the facade or interior fit-out is affected
• A change of use, for example from a shop unit to a home or a practice
• A tight schedule with several trades that must be coordinated
• A budget that simply cannot absorb a planning mistake

The project phases from analysis to handover

What the planning costs and how it is billed

Billing is usually done in two ways: as a percentage of the construction cost or by time spent. For renovations the fee typically lies between 15 and 22 percent of the construction cost, and between 12 and 18 percent for new builds. The hourly rate ranges from 120 to 300 CHF. The former SIA tariffs have not been binding since 2020 and now serve only as a guide, which is why comparing several offers pays off.

It matters to clarify which services the percentage includes. Some offers cover only the design, others include the tender and site management. Offers only become comparable once the scope of services is described identically. A low rate that later triggers extras is rarely cheaper than a transparent fixed price.

Basel as a special case: heritage and townscape

Basel has an unusually dense building and design culture, from the medieval old town to the works of Herzog & de Meuron. That culture shows in the procedure too. Anyone building in a protected zone or on an inventoried building must, according to our research, notify the cantonal heritage office around two months in advance. In the permit procedure the heritage office takes a binding position and can impose requirements on materials and detailing. That position is no formality: it can mean a particular window model, a historic floor surface or a ceiling height must be kept. Planning for this early avoids costly redesign shortly before work starts.

• The cantonal heritage office is responsible as soon as a building is protected, inventoried or located in a protected zone
• The townscape commission, made up of specialists, assesses building and design measures in the other zones
• Free building advice is available for many owners of buildings worth preserving
• A common requirement is to agree materials and details with the advisory service in advance

In Basel’s old town it is not the most beautiful design that wins, but the one that thinks fabric and permit together from the start.

Protected fabric versus a free hand

The Basel market and its old buildings

Basel is an affluent market, carried by the pharma industry with Roche and Novartis. That translates into strong demand for carefully renovated period flats, in Bachletten, the Gundeli or St. Alban. At the same time the building stock is old: in buildings from before 1991 an asbestos check is needed before any intervention, which affects both schedule and cost.

So budget realistically: a reserve of 10 to 20 percent is standard for Altbauten, and overruns of 15 to 25 percent are not rare without rigorous planning. This is exactly where the value of professional support lies, bringing fabric, permit and budget together from the first sketch. Whoever later sells or lets benefits from a careful refurbishment that keeps the character of the old building rather than smoothing it away.

How to choose the right professional

Compare not just the hourly rate but the service behind it. Ask whether the survey, permit documents and site management are included in the offer or billed separately. Request two to three completed references on comparable fabric, ideally in Basel itself.

A visit on site and a conversation with former clients say more than any brochure. Also check how communication runs: whoever is already hard to reach during planning will hardly be better on site. Clear responsibilities and a realistic schedule are worth more, for a Basel Altbau, than the largest portfolio.