I've used it as an office and a cool space to hang out and watch movies with my family. Currently, it houses my rowing machine and turbo trainer and I call it my 'palace of pain'! It has over 100 metres of LED strip lighting, and a huge pivoting action where two of the walls rotate to open up the space. The cantilever roof then floats above the space. It was featured on George Clarke's Amazing Spaces.
I designed and built the entire thing myself (with a little help from my Dad). I'd always wanted to start with a bit of land and then make something from scratch.