in discussion Hidden / Per page discussions » Swiss Political System: More than You ever Wanted to Know (II.)
Sorry, I didn't have time to get back to you until now.
Unfortunaly, I don't have a crystal clear source for my claim. Art. 29 Abs. 2 of the constitution grants the right to be heard (rechtliches Gehör). Apparently, a lack of reasoning is a direct consequence from this. The federal court summarises Art. 29 BV as "rechtliches Gehör und Anspruch auf einen begründeten Entscheid" in their 1P.228/2002 ruling against the city of Emmen.
Now, about my (bold) claim that can you appeal any decision by a governmental institution. I believe that this follows directly from Art. 29 BV, because a final decision by any institution would violate the right to rechtliches Gehör. Also, every decision I've ever received from my city or canton had instructions on the right to appeal the decision. In the canton of Zurich, an appeal usually first goes to the Bezirksrat (unless for some common cases, like taxes, where there are special first-instance courts like the Steuerrekursgericht), then to the Verwaltungsgericht, and then possibly to the federal court.