I thought of these two explantions and think that neighbor principle is pretty close to Nachbarschutz.
Neighbor principle:
Black' law dictionary: Doctrine that one must take reasonable care to avoid acts or omissions that one can reasonably foresee will belikely to injure one's neighbor.
Bayerisches Sozialministrerium: Sozialrechtsfibel:
Nachbarschutz
Jedermann hat im Rahmen der Gesetze das Recht auf ungestörte Nutzung seines Eigentums, seiner Wohnung und seines Grundstücks. Wird der Grundstückseigentümer in der Nutzung durch Immissionen von Nachbargrundstücken beeinträchtigt, räumen ihm die Vorschriften des Bürgerlichen Gesetzbuches einen Anspruch auf Unterlassung, auf Abhilfemaßnahmen oder auf Ausgleich in Geld ein.

Lord Aktin:

"Who then, in law, is my neighbour? The answer seems to be persons who are so closely and directly affected by my act that I ought reasonably to have them in my contemplation as being so affected when am I directing my mind to the acts or omissions which are called in question."

Thus "neighbour" is not the physical, next-door neighbour occupying a piece of land next to mine, but neighbour in the Biblical sense of "love thy neighbour" (from which Lord Atkin took his definition).

"persons closely and directly affected by my act" so that I should "reasonably have them in my contemplation".

It doesn't matter where they are and if you do have them in mind. The word "reasonably" tells you this (the "reasonable man or now person" principle)

Thus in the case in question a manufacturer of ginger beer with a snail in it was found liable to a young lady in Scotland under the neighbour principle. The young lady was not his next-door neighbour, but a consumer of the ginger beer in a cafe.

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Note added at 2005-04-23 12:53:51 (GMT)
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The duty of care that road users owe to other road users is another example of the \"neighbour principle\" at work, irrespective of any statutory liability that is imposed through legislation.

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Note added at 2005-04-23 13:45:01 (GMT)
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I would say that there is no real \"English\" equivalent as the rights of the immediate neighbourhood are defined negatively rather than positively.
The two torts that come into mind here are private nuisance and trespass.
The private nuisance tort is \"unlawful intereference with a person\'s use or enjoyment of land, or some right over, or in connection with it.\" (Winfield & Jolowicz on Tort - 15th edition, p. 494).

Thus the immediate neighbour has a right to be free of \"unlawful interference\" (private nuisance) and also of \"unauthorised entry to his land\" (trespass).

In both cases these rights are defined negatively rather than positively, which I think is probably the key difference between the different jurisdictions and which often makes translation so difficult, except, of course, where you are dealing with areas where the law is almost identical (EC law).

Caution is urged here as the right to "quiet enjoyment" is a covenant between landlord and tenant.

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Note added at 2005-04-23 14:00:48 (GMT)
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Ok it\'s \"quiet enjoyment\", rather than \"peaceful enjoyment\", but it could still be misleading.

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Note added at 2005-04-23 14:47:02 (GMT)
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Enjoyment on its own is OK.

Private nuisance has been defined as \"a tort to land. Or to be more accurate it was a tort directed against the plaintiff\'s enjoyment of rights over land\"

(Professor Newark in \"The Boundaries of Nuisance\" (1949) as citied in Hunter v. Canary Wharf Ltd [1997] 2 ALL ER 426)


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Note added at 2005-04-23 14:48:11 (GMT)
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Sorry about the spelling mistake - that should be \"cited\"

So saith Romain inter alia. ;-)

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Note added at 1 hr 54 mins (2005-04-23 13:53:50 GMT)
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...for example \"the adjoing owners\' legal protection against infringements to peaceful enjoyment of their premises\"

:-)

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Note added at 1 hr 57 mins (2005-04-23 13:56:53 GMT)
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Silfilla and Anne do make a good point in their comments, perhaps you could go ahead and use \"neighbo(u)\" - as in \"legal protection for the neighbor, for example, against violations of peaceful enjoyment of their premises.\"
:-)

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Note added at 1 hr 59 mins (2005-04-23 13:59:09 GMT)
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Of course I mean \"infringements to the peaceful enjoyment\" the entire time! ;-)

That's what they call it in the UK.

After all this, I have finally come up with a translation that might somehow bridge the divide.

In the Canary Wharf case it was stressed that the rights attach to the occupiers, whether they be owner-occupiers or tenants.

Thus an owner occupier or a tenant can sue in private nuisance, i.e. someone in exclusive possession, but not usually a landlord unless something terrible is happening to their property (such as serious vibrations affecting the foundations).

A guest at a hotel, although somebody's "neighbour" for a short time at least could not sue in private nuisance as the hotel guest does not have exclusive possession, but merely a licence to use the rooms.