Doesn't deal with the issue of photographing "sculpture or buildings" on private property though, (which the Abbey would be).
Being on private property and being in a public space are not mutually exclusive. I would think most properties are on private property. Many of them would be in a public space.
Edit: Having found the relevant legislation it appears that the public space requirement only applies to sculptures, the buildings exception is absolute.
62 Representation of certain artistic works on public display.
(1)This section applies to—
(a)buildings, and
(b)sculptures, models for buildings and works of artistic craftsmanship, if permanently situated in a public place or in premises open to the public.
(2)The copyright in such a work is not infringed by—
(a)making a graphic work representing it,
(b)making a photograph or film of it, or
(c)[making a broadcast of] a visual image of it.
(3)Nor is the copyright infringed by the issue to the public of copies, or the [communication to the public], of anything whose making was, by virtue of this section, not an infringement of the copyright.