For Colorado gardening, I would suggest the following items, of which there are many other's, but here's my top list:
Accessories:
Heaters - If you're living in the North, you will need to calculate the number of BTU's you'll require, to heat the entire structure. This can be done by a simple formula and tool, you can find one here;
http://www.minigreenhousekits.com/pages/BTU-Calculator
Fans - Vital
Automatic Watering & Misting Systems - Vital
Automatic Greenhouse Roof Window Openers - Vital [Depending Upon Location] (Usually they're default programing is to open if it get's above 73 degrees F.)
Shade Nets - For Southern USA greenhouse gardening, you would want to cover you're greenhouse, when it get's too hot. Generally, you will get about a 33% shade reduction factor from the traditional shade netting.
Glass Greenhouse Designs: Glass is elegant and something most people can't & won't ever have, simply, because it costs too much and can shatter, causing the greenhouse to be a somewhat dangerous place, when working around family member's and employee's even.
Polycarbonate Greenhouse Designs: Polycarbonate is the way to go, in my opinion, it's cheap, extremely durable, I mean it's virtually unbreakable, and it won't shatter like glass, but still provide similar see-through qualities. Poly panels can get very think, and provide excellent insulation, they are also easy to install and replace.
