Woman's in empty warehouse at which location? (5)
I believe the answer is:
where
'at which location?' is the definition.
(I've seen this before)
'woman's in empty warehouse' is the wordplay.
'woman's' becomes 'her' (belonging to a woman).
'in' is an insertion indicator.
'empty' says to hollow out the word (remove centre letters).
'warehouse' with its middle removed is 'we'.
'her' placed inside 'we' is 'WHERE'.
(Other definitions for where that I've seen before include "a question of location" , "enquiry" , "A question of place?" , "In which position?" , "At which point" .)