Assembles beds outside room upside-down (8)
I believe the answer is:
collects
'assembles' is the definition.
(I've seen this before)
'beds outside room upside-down' is the wordplay.
'beds' becomes 'cots' (cot is a kind of bed).
'outside' is an insertion indicator.
'room' becomes 'cell' (cell is a kind of room**).
'upside down' shows that the letters should be reversed in order.
'cell' backwards is 'llec'.
'cots' going around 'llec' is 'COLLECTS'.
(Other definitions for collects that I've seen before include "prayers" , "Accumulates, collates" , "Assembles" , "Gets or gathers together" .)