Wait, what? You have noise issues with neighbours and you are in a detached!? :O This is literally the reason I want a detached in the future if possible. Tell me this is unusual for the love of god.
I have a new build detached which we paid good money for. Walls are at least 40cm thick so have dense brick and thick insulation in them and we don't hear anything through the walls. On the one side we have a driveway between houses so plenty of space, on the other there is just a small path that the neighbor owns for access to their garden. He's retired, so no running and we don't hear anything except sometimes when the wind catches the gate and slams it shut but even then I think most of the noise is from our windows being open if it happens.
Unfortunately I can't say this is unusual or not. Seeing some newbuilds built like matchboxes and squeezed in like a game of dominos I wouldn't be surprised if it is a bit more common.