If you don't know what a growhouse is, the best way of explaining it is that it's like a mini greenhouse. They're much smaller and cheaper than a real greenhouse, usually constructed from metal poles and plastic supports with a plastic coat rather than panes of glass, but they do the same thing, which is to provide a wind-free, insulated, and hot environment for faster plant growth. You know how the air in your car is always horribly hot after it's been parked out in the sun on a summer's day? That's the same greenhouse effect these growhouses produce, except while hot car air makes you feel horrible, it makes plants feel fantastic, and grow far faster than if they were just outside in the normal air. A friend of mine put me on to using growhouses around this time last summer, and I'm glad he did. They're great things.
About this growhouse here, it's a three tier growhouse, and it's identical to the 3 tier growhouses sold in the likes of Homebase, Additions, or Podingtons (http://www.podington.co.uk/cloches-growhouses/3-tier-growhouse.html ) , except while Homebase charges a shade off £30 and the others charge £20-£25 before shipping, Poundstretcher are selling them for £10. I've bought two myself (one after the other), and I totally recommend them to you guys here.
They're best placed near walls in sunny areas, preferably face-on to the sun. Weigh them down with bricks, or there is a risk that they'll be blown over, as I've found a couple of times with my two-tier growhouses (which are made by the same company but cost £18 each, damned Homebase...). I found mine instore at the Edinburgh Gorgie branch, they should be nationwide. There's loads of other cool stuff instore too, like large plastic planters at £4 for 2, which is a bargain compared to Homebase.