Day 2 update:
The Sussex light was the first out the coop in the morning, I had to convince the rest out into the run.
I had to refill the water station because they had all the water! (Seems like a lot but that's a good thing)
They spent most of the day foraging around the run with the...
Thanks for the reply,
The chickens are 17 and a half weeks old, South West England, the coop has inbuilt vent holes which allows for ventilation, one nesting box as far as I know, the coop/run is designed for 8 chickens