Greenhouse options...

[Propergoodcollie]

I’ve only been into the hobby for about 5 years but I’m to the point that a greenhouse makes sense. I’ve been gardening for quite a few years. I’m at the point where I’m trying to decide on size vs price and homemade or purchased. I understand you get what you pay for and with that in mind I’m leaning towards homemade and that route would be cheaper as well I think.

 

[JudyB]

Will you be using it as a greenhouse, or a cold winter storage for your trees? And what type of trees are you storing if so?
I went with homemade, got the size I wanted, and it’s not transparent like a greenhouse you’d purchase as I don’t want too much winter light in there to heat things up and break dormancy. I used a opaque material called solexx.

 

[K_10_G]

I am in the same boat collie, I am leaning toward building a simple “hoop” house. My friend already has a bender for the poles at his farm. I hope to use it for overwintering and then will hopefully be able to use it in early spring to tinker with seedling / propagation. In the summer I plan to switch the 6mm plastic with a shade cloth for some of my more delicate trees.

 

[Kendo]

SOme consideration for green house material. If seams tight no wind issue.

http://www.northerngreenhouse.com/products/woven-poly/our-superstrong-woven-poly.shtml

 

[Wires_Guy_wires]

There are some pretty decent DIY kits available that allow some freestyling. If you want to create something unique though, it's going to cost a tonne of money.
To build both the structure and get glass cut to size, you're at the expense equal to nice car.

One thing I found very useful after a few days of working in greenhouses (and having to clean them in the worst possible conditions) is keeping maintenance in mind when designing these units. Don't put gutters in places you can't reach.