Are you sure you are talking about the Netherlands? Heating pipes routed outside walls I have seen in the UK, but never in the Netherlands. No soundproofing would NEVER pass building regulations in the Netherlands.
Waste water pipes outside are fairly common in some places with lots of older buildings but I don't think I've ever seen outside heating pipes!
Walls here are made from brick. The newer buildings are either normal or aerated concrete, and sometimes split up using drywall. This totally depends what the requirements are, and the past years, construction has been more and more drywall instead of brick etc. I've never seen a single layer of drywall, and I've lived in all type of housing in Amsterdam.