I'm going to convert a failed vegie patch into a shade house . 3.0 x2.0 . The patch turned out to be unproductive due to elevated position on reclaimed soil so the drainage was maximised and the plants suffered from a lack of water .
I rang the ABC radio gardening show and asked about the best way to do it and was told to go for a light shade cloth to allow for maximum UV but leave one end open to allow bees etc in to pollinate ,otherwise the vegies won't grow.
Ahh **** I thought to my self ,I have some sheets of polycarbonate and wanted to use them in the build but was told not to as they have a UV barrier in them and so using them would render the shade house as useless as the existing patch.
Hmm I might put a few sheets on the north facing walls to protect from the summer northerly's ,and a couple on the west/ south side to protect from the harsh winter winds seeing as the majority of the sunshine comes from above I reckon I'll be good to go.
It's a lot like home brewing really,experiment on a budget and go with works for you.
FFS I've just answered my own question