Hi Tales,
I think a wooden outhouse in this part of Derbyshire, in winter, would have been akin to Euthanasia !! All the old @*#* houses (you seem much too refined to know jokes like that) were brick built, and slate was relatively cheap here in Victorian days.
This structure was just meant for those personal moments ... However, there was quite a largish area at the very bottom of the garden that was concreted over, with the remains of an angle iron frame .. the shed that had once stood there had burnt down. When I broke up the concrete and started to turn over the ground I discovered that that was where they had dumped all their rubbish. I found a few nice bottles, jars old crock, clay pipes .. (I'll possibly post a photo of them on Oceans 'interesting finds' thread). That is where the girls now live (hens)