It's not required that Building control are notified but an installation certificate should still be issued.
Material costs can also be slightly higher here it's not unusual to find materials cheaper on the internet than I can get them from my wholesaler.
I've fallen foul of trying to install downlights once the PVC panelling has been installed it's a pain in the rear without a drawing or photographs. The more complex the timber work above the more of a pain in the rear it is.
At the end of the day it is arguable that the lad took his time to get it right and the finished job is to a high standard.
As for not getting a quote or estimate... lesson learned.