«With Wowoni, I want to create a platform that helps tenants better assess their situation.»

My name is Joel. I work as a software developer and am a tenant in Zurich. Like many others, I didn't know what rights I had – until it was too late.

For a long time, I was not aware that rent prices cannot simply be set arbitrarily depending on the situation.

The Trigger: Out of the Sublease.

I had to leave my apartment and needed something new quickly. If you know the market in Zurich, you know: You take what you get.

I was lucky in misfortune and found an apartment in the immediate neighborhood at short notice. Same area, same street, similar standard and a few houses away.

The catch? The rent was more than twice as high. Instead of CHF 1,200 (old apartment), I suddenly had to pay CHF 2,800: Both ~50m² living space and older buildings.

Missed the 30-Day Deadline.

I had a bad feeling, but I signed. I thought: «That's just the market.»

What I didn't know:

  1. There is a maximum allowed return (based on the reference interest rate + surcharges).
  2. I could have challenged the initial rent within 30 days.

Because I was stressed with moving and didn't know my rights, the deadline passed. After that, I was bound to this price, even though it was likely too high, and probably still hovers up there. Over the months, such a difference adds up quite substantially.

For a Rental Apartment, a Maximum Return of 3.25 Percent is Allowed.

For newer buildings, up to 1.5% is added depending on the situation.

The Burden of Proof Lies With Tenants.

I was annoyed. Not just about the money, but about the system. Landlords exploit ignorance and housing shortage to enforce prices that would hopefully not hold up in court – if you challenged them in time.

That's why I built Wowoni (formerly kreispreis). I want to visualize data points and make rental law so simple that no one misses the 30-day deadline or gives up out of fear of bureaucracy.

Don't Simply Accept High Rents as Fate. Educate Yourself, Network and Use Your Rights.

The process is tedious and complicated. It currently requires a lot of patience and time to review the rent, and the chances of success are not always certain. «Being right» and «getting justice» are two different things.

For You, Me, and All Other Tenants.

Wowoni is my contribution against rising rents.

Joel, December 12, 2025

Your Rental Information – Your Contribution to Fairness.

Alone, you're powerless against unjustified prices. But when we share our data, we turn the tables. By sharing your rent, you not only help others – you also gain access to comparison data from your neighborhood. End the silence about rental prices.

Share Your Rent Now