I’m assessing a 4-bed duplex in Berlin at €1,224,000. Expected rent is €3,558/month, giving a headline gross yield near 3.5%. I’m assigning nothing to appreciation. My base case includes vacancy, management, routine maintenance and a larger-repair reserve, but vacancy still changes the result materially. The building appears sound. Which local cost am I most likely understating, and what net yield would compensate you for the risk?