For those who can recall, living in an “Altbauwohnung” (apartment in an old building) in the middle of the city center can be tricky. I am the first defender of old apartments don’t get me wrong. I love to hear original wooden floor cracking under footsteps and the high-ceilings, higher than ever. If you got the kitchen and the bathroom renovated you might have won the jackpot. It’s truly charismatic and each apartment has its own vibe. The only minor detail is that often old buildings have bad isolations and windows, which means that over the summer it gets really hot and really quickly. Last summer, there was a heatwave in Zürich and it…