FINALLY after several days of construction (nothing LIKE the 8 hours the instruction book predicted) we have our greenhouse! It's 11 x 8 foot (2.59m by 3.89m), with double doors and 4 roof vents. It's made from twin-walled polycarbonate, and the frame is also polycarbonate, so no metal to absorb the cold.
At the moment I have some old tyres and a black bin full of water to act as temporary heat sinks while Jerry works on the plans for a solar powered heat sink. So I just have a few frost sensitive things in at the moment (strawberry, avocado, tomato).
For a pictorial tour of the construction and the insides of the greenhouse look at the photo gallery on our flikr site:
http://www.flickr.com/photos/nigeandgabs/sets/72157600362382717/