Thanks for all of your quick replies.
I definitely plan to test the installation once complete.
There was previously a similar circuit in the garage but due to roof leaks (now fixed) and old age, I decided that I ought to replace the existing electrics as the old one looked...
I was thinking of installing the following electrics in my garage. I have done lots of research but can someone else confirm that this is all ok:
1. 2.5mm cable from consumer unit in house (16A fuse and RCD) - already installed.
2. Switchfuse unit or will a normal switch do?
3...