In the denser parts of Switzerland, apartments are very common. I don’t see how solar works when people are living in a 5 story building. I couldn't see solar working that well where I lived in Lausanne, for example, at least on a person housed/energy unit basis.

Five floors probably isn’t too bad, thought of course that depends entirely on how many people in each apartment and how large they are — e.g. one person in a 50 m² place, divided by five floors, with 20% efficient panels, 25% duty cycle for night/latitude, still implies 500 W, compared to the average electricity consumption in Switzerland of about 900 W per person. It’s not everything but it’s also a pretty impressively large number.

(Something I only found out by looking up Swiss energy consumption: apparently Switzerland produces just over half of its current electricity from hydro power, which makes sense considering the terrain).