Search for empty cell in a row, highlight a range in that column

I have sheets detailing inspection plans and am trying to include a log of the inspection checks into the same sheet. When characteristics in column A are changed I'd like the sheet to automatically highlight and record this in the log section. I was previously doing this with 2 separate sheets but I now need to combine the 2.

I've included a before & after to show what I'm looking to do.