Hi @SebStripp,
It says you ran out of disk space since the Radiance octree of your model is huge. However, I believe this is because of the Shades in your model. Some are duplicates and I think this is messing with oconv, the Radiance program used to create the octree. I tried to add the Shades in the end as shown in the image below and it runs without issues.
SchoolHBModelRev03_Edit.gh (745.9 KB)
Btw, you might want to mesh the floor surfaces as seen below. This will give you a uniform grid instead of some grid faces being triangles.
Final remark… If you find that the daylight factor results are odd you might want to increase the ambient resolution. You can see more about that here or here.