VRDP11350 | Building alterations [items 8 to 13]: widening a passage
From HM Revenue & Customs · VAT Relief for Disabled People Manual
It is clear from dictionary definitions and legislation such as the Building Act 1984, Section 84 and the Public Health Act 1936, Section 78 that a passage can be outdoors.
External passages are entitled to the relief, whether supplied to a disabled person in their private residence or to an eligible charity building, such as the widening of a narrow path across a churchyard to accommodate a wheelchair.
However the works:
must relate to an existing path; and
should be confined to the curtilage of the property (legal owned land) - see VATLP for further information.
Zero-rating would therefore not apply to the:
creation of an entirely new path for wheelchair access across church grounds; or
the provision of a minor road outside the curtilage of the property in question - see V1VATLP for further information.