Thanks, Oldsie! I'm after a 10 x 12 to go on the base that's there already. There's currently a strange pavilion-type thing that, I suspect, they <strike>nicked </strike>got on the cheap from a bowls' club or something. It's decidedly wonky and is not ideal because it doesn't let in enough light. There's a nice-looking Robinson 10 x 12 on there at the moment with no bids and starting at £75, but it's miles away in High Wycombe and too much for us to dismantle anyway. Quite what I would do with 12 feet long base lengths in my little car is another matter, in any case! I'll keep my eyes open for something closer. Thanks for the tip about cold frames. Now that is a good idea!!