Hi and welcome to BYC. Here are some helpful links:
Great go-to resource including coop design ideas - Articles
https://www.backyardchickens.com/threads/topic-of-the-week-keeping-chickens-cool-in-summer.1181934/
http://www.backyardchickens.com/t/788391/keeping-chickens-cool-in-summer-heat
How...