It was a hole and I had to crawl through it to install the extractor fan. I think I need to start Pilates in the new year to improve my contortions at work. The over cubicle light sits in the centre of the ducting for the inline extractor fan sited in the loft space above. The ducting leads towards the gable end where a 100mm core was made and a wind proof exterior vent grille put on the outside.
Interesting job this week trying to replace some overloaded guttering with deep flow on a tall chorlton property. The glass roof preventing access for a single ladder. I was able to fix ply boards between the glass panels which my smaller ladder could go on top of. All went well and the guttering is now installed. It'll probably be getting snow before any rain.