Grass rendering through objects?

I’ve made a scene with a building and grass made using hair strands, and when I try to render a very small strip of grass renders in front of the building for some reason.

I’ve tried changing the camera angles and moving the object with the grass around and it seems to consistently occur.

Anyone have any idea why this might be? And what I can do to fix it :confused:

It’s rather an urgent issue, as it’s part of my coursework, which has to be in by Wednesday (including a video render), so I need to get this fixed asap…

Thanks in advance :slight_smile:

(The problem grass in the image is just below the red balcony)