What a great project this is, building your own greenhouse! If you're a gardener, then a greenhouse is necessary no matter where you live. As long as you've got some good plans, it's possible to build a backyard greenhouse within just a few days. It's a great way to impress the neighbors! Metal greenhouses are practical, I agree, but they look ugly. If you build your own backyard greenhouse from wood, you'll end up with a lovely looking Victorian-style greenhouse, which will last very long if you treat it with the correct wood protection. Of course you'll save a lot of money in the process too. How much exactly? It's difficult to say as it depends on how much glass costs where you live. After all, there isn't much wood required, as it's only the actual frame  that is wooden. To make sure you save the most money, it's best to take your plans to wherever you plan to buy your materials. That way you won't end up wasting any money on unnecessary materials. To be honest, saving money is not the main reason for building your own greenhouse. It's the fun you'll get from building it and the pleasure you'll get from showing it off to your friends and family that makes the project worth doing. Nothing beats the feeling when someone asks you where you bought something and you turn around and say "Oh, actually, I built it myself!" That feeling is priceless! You'll never feel like that over something you've bought! In writing the passage, the author's main aim is to   _  .
tell people how to save money when building a greenhouse teach people what to do when building a greenhouse discuss whether people can build a greenhouse by themselves persuade people to build a greenhouse by themselves