How big a greenhouse are you considering? There are lots of kits out there in all kinds of price ranges. I've browsed a bunch of them, big and small, from hoop houses to glass. google them and you will find all kinds of information. Look at both garden supply and farm supply catalogs and sites. If you are going to get fairly complex and need to look at air circulators, solar lifters, heaters or roll-up panels, benches, etc. look at the farm supply catalogs.

Also look through the ads in garden magazines--both the big ads and the small box ads that usually run in the back pages.

I'm in the USA so the suppliers I am aware of wouldn't make sense for you. But for good information about materials, check out www.GrowersSupply.com. Their catalog has a wealth of information-I am assuming their website provides the same.

Janie

Glass will last but will cost. Plastics vary a lot