Using block is a good idea, great for washing down the interior of the coop....no frost line here in GA...but block around here are $1.65 each...+ morter....perhaps you can get free ones at building sites that the builder will be happy to give up...ask first however....five finger discount might get you shot. I'm using used rusty metal chicken hse roofing for roofing and 2' interior walls...outside is 1 x 8 vertically.
Happy Hatch'en
Happy Hatch'en