Cheers. I must admit I've never used grid switches. In the lobby has an existing double switch controlling interior light and outside light on the house. I assume that could be replaced with a grid switch assembly incorporating those two existing functions plus the wireless switch to the shed. Inside the shed to give a local switch appearance doesn't matter.
However I've still not written off PIR as the best option even if that was only for "approach lighting". I don't think anyone's commented on my initial question, can more than one be installed in parallel?
The requirement is getting a little more immediate, as in a week or so all weekday poultry operations are going to be in the dark both morning and evening, so lighting the work area would be a big benefit. As a temporary measure I've fitted a PIR that I had lying around, and a simple bulb holder. That should give some idea of range and coverage.
