HOAs do exist in Europe too. Because it's impossible to coordinate maintaining shared property without them.

The central heating system is showing its age. With what technology will it be replaced? Gas? Oil? Heat pump? A connection to district heating?

If it's a heat pump, should you put solar panels on the roof? If so, who pays for them? Everyone? What if some don't want to? How will revenue be shared if only some are willing to pay the cost? How will you calculate how much it costs to heat one apartment whose owner shares ownership of the solar panels versus how much it costs to heat one apartment whose owner doesn't?