
In my opinion, the 2 keys are what your intention is (whether you wish to have a walk in greenhouse OR a stand-alone unit) AND the amount of light that is already existing in the area you wish to put it in. I say this because if there's insufficient light in the area you want your greenhouse, you'll have to build a much sturdier unit that will support light fixtures, etc. In my opinion, this is something that would require customization according to your specs (obviously much more labor-intensive and costly). If you want to have your greenhouse in an area that already has a great deal of light that factor is already taken care of and you need only be concerned with ventilation and humidity. Of course, if you want a greenhouse that you can walk around in (I think someone mentioned this) and you also have a great deal of light, this will also require customization according to your specs (similar to a commercial greenhouse). Sure, I'd like a greenhouse that I can walk around in but I have to settle for what I can fit in my kitchen, where I already get a great deal of light. I live in a condominium and cannot build onto my unit nor do I want the expense - so I have settled for what I have. But I've seen many greenhouses made from large aquariums (which someone also mentioned) that are very, very attractive. It's a matter of what you want, what you already have to work with, whether you already have plants and what sizes they are, how much you're willing to spend, and how much work you're willing to put into it! Simple, huh? LOL!! The attached photo is typical of what I'm growing in my mini greenhouse.