You Are At: AllSands Home > Gardening > How to build a greenhouse
A green house is a building made of glass or other materials that has a controlled temperature for the purpose of cultivating plants. There are many different types of greenhouses on the market today and although they can be purchased in easy to assemble kits, you will get the best results by designing your own.

The first thing you will need to decide is the type and size structure you want. Next decide how much money you are willing to spend. When doing this always provide for expansion by planning for more space than you anticipate using. Then check with your local building department about permits another other regulations before you begin. Kits come in a variety of styles and ready to assemble. You can purchase any greenhouse in kit form from a simple window greenhouse to one that is freestanding and fully equipped. If you are interested in using a kit, many catalogues are available to order these from or you can check with you local hardware store for prices. But, if you prefer to build your own customized greenhouse there are many styles to fit your needs no matter where you live.

Building your own greenhouse will give the satisfaction of growing vegetables in December and orchids in February. While snow covers the ground you can step into another world of tropical delights. Your first considerations when you have decided to build are how big, prefab or build my own, building permits, local design ordinances, set back requirements for your property and location of the green house. Other considerations would include maintenance cost, heating cost and taxes.

To determine how large your greenhouse should be you first need to consider what is affordable. Greenhouse growers around the country agree that you should make it larger than you anticipate since once you start gardening you will want to expand. When considering prefab or self built green houses plan according to your available time and money. You should also consider what it is you want to do with your greenhouse. If you're quite the novice at building you will want a prefab or to hire an experienced carpenter to build for you.

Many people want to know if a greenhouse will increase their property tax. Fortunately many states are enacting laws to give tax rebates on solar heating devices and if you choose the right greenhouse it might qualify. Your local building inspector will be able to help you with your building permits and can give local design ordinances. Be sure to take a simple drawing showing the dimensions and supports when you visit with the inspector. In most areas building have to be set back a definite distance from the property line. Be sure you check to learn what this distance is in your area before you begin building. Check with your local utility companies to get some idea of the cost of supplying heat and water to your greenhouse. In most cases, if the greenhouse you build is solar you will have no heating cost. Even adding a layer of plastic sheeting to the inside can cut your heat loss up to 40 percent. Find out if your greenhouse will be considered a temporary structure and if it is, you may not need a permit or to pay any additional taxes.

One of the most critical first steps in designing a greenhouse is to decide where you will place it. The first consideration should be sunshine. During the winter months the sun will be a lot lower than in the summer months. Look around the location where you are planning to build. Check for trees or fences that might block the sun. As a rule your greenhouse should be located a distance away that is 2 1\2 times the height of wall or house to keep the sun from being blocked. If a tree is deciduous it will provide shade in the summer but allow sunlight in the winter when its leaves have dropped. Your site should be relatively level. If you plan to use the earth below the greenhouse for growing check for rocks, clay, and drainage. You will also need to determine the closest route for water and electricity to your planned site. A site that is closer to your house or attached to you house will save you a considerable amount in this area.

Next you will need to decide the style of greenhouse you will build. There are A-frames, free standing, attached and gothic. An A-frame can be built in sections on the ground and then raised into place before covering. The free standing can be built to any size and covered with anything from glass to polyethylene. The attached is becoming very popular since it can be heated from the house or if it is solar, the heat from the greenhouse can be transferred to the house. This type of greenhouse is easily accessible from your home regardless of the weather. The gothic has a roofline made from laminated wood strips. Since wood is used, permanent coverings such as corrugated fiberglass can easily be installed. Glass is the most popular medium for covering a greenhouse. Clear acrylic, fiberglass and polyethylene film are also good.

Most kit manufacturers will provide foundation plans and installation instructions for a greenhouse. Mild climates allow a lightweight greenhouse to rest on the ground secured by rods. Colder climates will dictate a foundation footing of poured concrete that must extend below the frost line. If your greenhouse is not attached to your house it will need a thermostat controlled heating system. The company that sells you the greenhouse should be able to recommend the correct size and type unit you will need. You will also need one or more roof vents with an automatic opener to maintain the proper temperature. Locate other vents in the sidewalls. It is also wise to install a battery-powered alarm to warn of sudden changes in the temperature of your greenhouse. You can use roller blinds on the outside of the roof for shade but it is wise to use a rain resistant shading paint on the outside if your greenhouse walls are glass. This is a cheap and effective way of shading and the paint will wipe off when you no longer need it.