The greenhouse now departing...

I've started work on demolishing our greenhouse. If I didn't, it would fall down in the not distant future, probably because a cat or two were bouncing up and down on it. It is an interesting home-made design, which probably worked well for quite a few years, but recently it's been leaking all over the place despite major repairs, and there is no hope for it. I only remembered to photograph it when I'd already removed the door (or rather, permitted it to fall off), and the glass from the near side.
I'm intending to replace it with a garden room, which will be the most major DIY undertaking I've undertook, so I am trepidatious! There has to be something there, because Eggy likes sleeping on top of it, and who am I, a mere human, to deny a cat its rights?