Worth pointing out that in the world of broiler production 40x500 is tiny. When a commercial vet came to our place to blood sample our little flock of 28 he bought with him three trainees. He explained that they were with him for the day and he was going to show them the extremes of chicken keeping. Their next visit was to a broiler plant that had 200,000 on the site!
So by my calculations, to be competitive with economy of scale, you would need 8 of those houses (one empty being prepared). Add to that the processing facilities (slaughter, packing and freezing), plus the cost of the land and the total investment needed may be around the £4 million mark.