Moving to London recently was an eye-opening experience. I came from Frankfurt (one of the most expensive German cities), yet finding a place was astronomically harder and in the end we pay around twice what we did for a similarly located (but smaller!) flat.
In general most housing seems to be much worse quality as well. Our current place is actually quite nice and feels very solid/well insulated, but many places that I viewed (or briefly lived in) were really run-down, poorly insulated, or clearly just poorly-built.
I’m not sure if it is one of the causes, but we were also looking into buying a place here and found that owning (and presumably building) anything other than single-family houses is a bit of a clusterfuck (here in England at least, I’ve heard it’s better in Scotland) with the whole “leasehold” system.