Buying a greenhouse kit from a local business had many advantages. I could stand inside different models and experience the space firsthand. Rick Warner of Sturdi-built visited my garden to help me select the best site. The friends who assembled the kit for me went directly to the shop to get tips about pouring the foundation and cutting the glass. But even if you buy a mail-order kit, you'll save money and get a standardized product that has been tested and refined.
Resourceful gardeners can build a greenhouse from scrap materials.
Gavin Younie of Portland, Oregon, reclaimed an old awning frame, windows, doors, and other castoffs for his backyard greenhouse. A custom-built greenhouse will usually be more expensive, unless you build it yourself and have the ingenuity to find recycled materials like windows, patio doors, and scrap wood. My teenaged friend Gavin Younie, an avid gardener, did just that. With the help of his father, Gavin built a free-standing greenhouse mainly with materials he scavenged. If you want to grow orchids you'll need a taller, warmer greenhouse with better insulation, fans, and heaters than if you want to start cuttings and grow seeds of hardy herbaceous perennials.