So my idea of setting up a polycarbonate hothouse is not going to happen. After a lot more research and asking my good friends over at Down To Earth on their thoughts I have decided to look at another possibility.
My main reason why is due to wind. We live on a hill and where I was going to put the hothouse is exposed to some pretty strong winds all year round, unfortunately there seems to be a strong possibility that my expensive hothouse may end up in pieces all over the neighbourhood.
So on to plan B. This raised bed will now become my hothouse, it's smaller than what I would like but will not cost a lot to set up.
I will be taking out the soil and using it for the other raised beds, the wooden base will be kept and I will make a structure (possibly igloo style) to go over the the bed with steel droppers and polypipe. Plastic will be fixed over the top with air-flow at both ends.
Sounds easy doesn't it? I just have to get over this flu first.