^^ sounds like friend's new house. PU pipe and copper pipe joined just by jamming the 2 together. Hot water feed to bath. Presumably the coefficient of expansion of copper and plastic differ. Made tracing the source of the leak much easier when the water p1551ng thru the ceiling and down the kitchen wall was actually hot.
Dutch plumbing and electrics was dire when I lived there. They're cheaper than certain stereotypical demographics in the UK. Wire was *really* invented by 2 dutchmen fighting over a a 1 cent coin.
Combi boiler needed topping up weekly in summer, and daily in winter. No clue where the water went, but It wasn't into our apartment. Take a shower and you had 4 minutes exactly. After that, you'd be scorched to death and the boiler would trip off. No gas technician / plumber ever managed to sort that until they ripped the whole lot out (was less than 10yrs old) and started again.
Pipe work was apparently a bit "iffy". So they fit a restrictor by the meter to lower the pressure. Nice one. Shame it took 20 minutes for a cistern to refill (and only take about 2/3rd of the water a UK bog takes!). So if there's more than one resident, make sure you don't do a double-flusher in the morning else one of you will be late for work.
Electrics - only plugs in bathroom/kitchen are fully earthed. The rest are unearthed 2 pin, and fitted to walls made from panels with the consistency of chalk, held together by the wallpaper.