The Best Greenhouse For You Before you do anything�even before you start dreaming about building a greenhouse�check with your city engineer or building inspector. It is important to know what the building regulations are as to greenhouse placement and construction. In some residential areas, construction of any kind of commercial structure is prohibited. Find out everything about all relevant laws�and don't consider yourself "too smart" to need a lawyer.
To build a workable greenhouse, you will need a construction plan. Then you can consider ways and means. There are several ways to go about building. You can draw up a contract with a manufacturer of greenhouses to supply all the materials, all the heating and cooling equipment, and the masonry. You can even get him to find you a builder to erect the structure, and also a plumber for the water and heating installations. Or you can purchase the material you need (new or used), and have some local labor come in and build your greenhouse. Or you can do it yourself, perhaps with some help from your family.
If you prefer the prefabricated units, you can erect a greenhouse with little or no extra help. You can glaze it with regulation glass panes, Fiberglas, or plastic. Ready and able to supply all this are innumerable firms. As you plan your greenhouse, there are further decisions you will have to make.
Where to Place Your Greenhouse You must decide upon a site, and this involves several considerations. You want a location where you can work conveniently and where there is maximum sunlight. Even though you may plan to start with only shade-loving plants, you will probably find that other kinds are profitable, too, and so eventually you will want to be able to grow light-loving plants. You can always apply shading to make a house darker, but you can't make the sun come around to a greenhouse that has been unwisely located in a shaded place. Fluorescent and incandescent lighting can be used to raise light intensities in winter and on dark days, and this is a very practical means of utilizing small problem or special-purpose areas (as discussed later). But you certainly don't want artificial lighting to be your primary light source�not while sunlight is free! Therefore, you want a location with a south-eastern or southern exposure, and the land should be well-drained. Then, for the sake of customers, you need a location which is easily found, and where parking will be easy.
If your eventual aim is expansion�that is, having a series of greenhouses�plan that series from the very start. Make your first house fit in�on paper�with those you will build later, so as to form a complete unit. Many greenhouse operations start on a small scale but soon need to expand, so select an adequate site at the start.
What Type of Greenhouse? There is a type of greenhouse to meet every preference, every gardening need, every budget. I have seen sun porches and chicken houses converted into greenhouses; greenhouses built as second-story units over garages; free-standing or detached greenhouses; step-into pit houses, and many kinds of attached-to-dwelling ones. There are heated, partially heated, and unheated greenhouses, each successfully designed to suit someone's gardening-for-profit plan. Greenhouse designs are numerous but types fall into these main divisions: span, lean-to, uneven or partial span, and the pit house, which may be any of these types but with a greater portion of the walls below ground level. If you have plenty of room�real acreage or a large lot�the free-standing span house may be best for you. This type, if properly placed, receives maximum sunlight throughout the day in every season. A lean-to, as the name suggests, is erected against the side of another building. The partial span or uneven type has a greater distance from eaves to gable on one side of the house than on the other. In the north, the low winter sun comes directly through such a roof for maximum light. And in the summer, when the sun is high, this greenhouse draws light reflection from both sides.
The cost of pit-house construction is low. Many growers use pit houses only during early spring and into fall. They are left idle during the coldest months of the year to avoid a heating bill. Other growers operate a pit house economically by having it dug off the basement and served by the household heating system. This arrangement affords ample space for potting, household tools, and other necessary equipment. Although curved eaves make a handsome greenhouse, there are no special advantages in them.