For permanent coop, a concrete would help the termites from directly chewing/eating the woods if they were put above the ground. Just keep regular inspection for any soil routes that these termites can made just to get your wood later.
On 2nd thought, how about those chicken tractor that were made out of the wood ? Many of them out there, that I've seen here will put their woodly made chicken tractor to get in touch with soil/ground level...Any ideas guys ?