I'm building a chicken house

Welcome winter! The rain, the darkness, the cold. But i have a lot of time on my hands and an overactive imagination. So I have decided to build a chicken house. I looked online for some ready made ones, but they are all over £350!! It's a chicken for goodness sake. And those things aren't even luxury chicken hotels with full en suite jacuzzi baths. They are basically wooden boxes.
So the first thing i need is some wood for the frame. Now for some reason the demented mutants who owned the house before me decided to decorate the kitchen ceiling in semi mock tudor style. Of course that means artex patterns with dodgy bits of black painted wood strips pinned with 3000 rusty nails, half hammered in at no useful angle and with no apparent thought or purpose. The whole thing looks like i'd built it. After a ocuple of gin and tonics. (Let's face it, that would be the only reason something like that would come into fruition. It always seems like a good idea at the time.) I've tried to get the wood strips off, but they wont budge. Time to bring in the husband!