Cutting a hole in the wall for a door

I am planning to build an en suite bathroom in the adjoining bedroom, with access from our bedroom. To do this I will need to cut a gap for the door into the brickwork. The wall itself will be on the top floor of a two storey house but it is a structural load bearing wall (joists in the loft).

Will I need add a lintel or would the door frame be sufficient? The distance from the top of the door gap to the ceiling is about 40 cms.

Alan.

Loadbearing thus will need a lintel.

...as your BCO will no doubt indicate to you...