[NorthEssexsmallholding]

Came across this whilst looking at how to build your own polytunnel, its a step by step guide. 

Although I suspect sourcing the materials may not be as easy for everyone as this chap makes out, you can barely step foot on a building site these days without being told to go to the site office for a H&S induction and be issued with a hi vis and hard hat.

But if you can get the materials you would save hundreds by building one yourself.

http://www.overthegardengate.net/UserPages/pp_view.asp?FName=Polytunnel&Page=1

[Hermit]

I have recomended that build to loads of folk, it works well. But it must be taken down after the summer as they say  they dont keep their shape after high winds and snow falls. I have a mini version with an enviromesh cover I grow my brassicas in , you can put even minier versions on raised beds. Glad you could get it on here , I am useless at computers.

[Blonde]

to build a poly  tunnel house 

 YOu need to steel post either side of the  to make the frame.  they can be 3x3 metres  apart.   Take a pice of 2 " poly tube and lside the end s over the posts.   Do this to all your posts that you have put in the garden.  Take a piece of tubeing and attach to the  top  to fix the hoops together    Take a piece of shade cloth and put over the frame work.   You can add plastic over the top of this also to give a warm heated house.  Make a front and back section and add in to make a complet house.  You can make this house as long or as short as you want by adding posts and hoops