It's a bit of a step (5)
I believe the answer is:
riser
'it's a bit of a step' is the definition.
('riser' is part of 'step')
This is all the clue.
(Other definitions for riser that I've seen before include "One who has stopped sleeping" , "Upwardly mobile type" , "Bit of a step up?" , "Person getting out of bed" , "Vertical piece between stair steps" .)