Ned Deily reports coming across this sign in a San Francisco store window:
IS UNDER 24 HR.
Yes, this premise is, rather than these premises are. The result is something that looks like an instance of the logical term premise (so that Deily posted a photo of the sign on Facebook under the heading “department of rhetorical security”), rather than the ‘house or building’ word.
The ways of plurals in English are intricate indeed, and premise(s) exhibits several of these intricacies.
The history of premise is fascinating. The logical sense was extended some time ago to cover ‘an assertion or proposition which forms the basis for a work, theory, etc.; an initial or basic assumption; a starting point for reasoning’ (OED draft revision of September 2009). From this we get a metaphorical extension to a legal use, in the plural only: ‘the subject of a conveyance or bequest, as specified in the opening part of a deed …; the houses, lands, or tenements previously specified in a deed or conveyance’ (from 1464). And then to a legal use, and eventually to more general use, still in the plural, in the sense ‘a house or building together with its grounds, outhouses, etc., esp. a building or part of a building that houses a business’ (from 1610).
The ‘house or building’ noun premises is then a plural-only noun, as eaves is for most people: a noun that is plural in form and plural in syntax (while being, at least arguably, singular in reference), but has no counterpart singular form and doesn’t allow singular agreement.
Such a plural-only noun is likely to be reanayzed in one way or another. For instance, it can come to be treated (on the basis of its semantics) as allowing singular as well as plural agreement, like crossroads (CGEL has a list, p. 1589, of nouns with bases ending in /s/ or /z/, many of which allow singular as well as plural agreement). In fact, the OED notes this development for premises, with one cite, from 2005, for “every premises”. And there are many thousands of Google webhits for “this premises”:
This premises is now closed (link)
Ideal for a retail or bulky goods store, or even as a storage facility or office space, this premises is perfect for anyone seeking good public exposure. (link)
Another possible resolution of the disparity between form and semantics for such plural-only nouns is “singularization”, the development of a variant that is singular in form. This is what happened in the shop sign that Deily noticed. You can find a few more examples on the web:
Personally I have always liked the nice touch of the sign that said ‘This premise is guarded by a 357 Magnum five days a week. Its up to you to figure out which five days.’ (link)
Grocery stores have made us comfortable with signs like “this premise is under surveillance.” (link)
But “this premises” is much more frequent than “this premise”.