What type of greenhouse structure you need depends on where you live and what you want to grow. Greenhouse structure types and designs are categorized in a variety of ways such as temperature or structure.
Temperature
The spectrum of greenhouses based on environmental temperature needs include the following types:
Cold Houses – Temperature can go below freezing 0C. This types provide protection for plants. However, temperatures still can get below freezing because there is no additional heat source. The purpose of a cold house is to extend the growing season. In the spring by allowing the crops start earlier and in the fall by allowing the crops to grow longer.
Cool Houses – Temperature averages 45-50F/7-10C. This type of greenhouse will maintain temperatures above freezing so that plants that die from extreme cold can survive.
Warm Houses – Temperature averages 50-60F/10-16C. Allows for a broader range of plants to survive cold winters.
Hot Houses – Temperature averages above 60F/16C+. Hot greenhouses maintain tropical plants such as orchids. In order to heat efficiently and consistently, they require supplemental heat.
Within each of these general types, there are many considerations to account. There are very simple greenhouses and highly complex ones. The more you involve technology, the better the ability to control the growing conditions, temperature and water and moisture levels. Thee is even a greenhouse design that minimizes direct sunlight (a shade greenhouse) and not have walls, or a screen-only structure to keep out insects.
Conventional / Free Standing
The Post and Rafter design along with the A-frame are two of the most common greenhouse structures due to the simple construction of embedded post and rafters. This design is among the strongest with the rafters lending support to the roof. As the design is top-heavy, the frame must be footed, which will increase costs relative to other design options.
Covering material options: Typically glass, however rigid translucent polycarbonate glazing panels are now being used in many kits (lowering the overall cost relative to glass).
Ideal location: Open field/backyard, south facing.







A-Frame
Another popular greenhouse structure, the A-Frame. Rigid truss greenhouse or a peak greenhouse are other common names. The key advantages are its simplicity of design and minimization of materials versus other similar structures. It is one of the strongest styles of greenhouse and common uses for retail greenhouses or institutional greenhouses.
The popularity really falls on the simplicity of combing and roof and side walls together to create a singular triangular structure. The base can be either narrow or wide and works well in cold snowy climes as the snow doesn’t stick on the roof causing load issues. Finally, the long sloping sides create a significant amounts of sun surface and accommodates tall flowers or trees.
Covering material options: Typically glass, however rigid translucent polycarbonate glazing panels are now being used in many kits (lowering the overall cost relative to glass).
Ideal location: Open field/backyard, south facing.




Gothic Arch
A variation of the Quonset design, it includes a arched frame manufactured from galvanized pipe or conduit. A gothic arch greenhouse provides a traditional appearance and superior functionality.
They have been used with success on numerous types of growing operations, and since the internal environment can be easily controlled, they are an excellent and cost effective option for growers in any region. The frame is usually covered with plastic sheeting.
Covering material options: corrugated polycarbonate, plastic sheeting
Ideal location: Open field/backyard, with north-south orientation.




Hoop House
The hoop house gets its name from its shape, although houses can be constructed with straight lines using elbows to get the desired shape of the structure. Hoops use aluminum pipes or plastic PVC pipes and use a single layer of polymer plastic covering; a second layer may add additinal insulation. Hoop houses are one of the most inexpensive designs. Overall construction often costs less than $1 per square foot.
Covering material options: Plastic sheeting
Ideal location: Open field/backyard, with north-south orientation.






Lean-to or Attached
This greenhouse shares a wall with your residence, traditionally built off the back of the home or garage, but you can build it on the side depending on the orientation of the home.
Covering material options: Glass is typically used as the greenhouse structure is attached to the home but depending on your planting zone, some have used plastic sheathing.
Ideal location: The greenhouse should ideally be attached to the side of the home with a southern exposure.





Window
Also called garden windows, greenhouse windows or even bay windows. They are an excellent option for growing herbs and small plants within the home. Instead of using single pane of glass, the window extends off the exterior wall of the home allowing maximum light penetration.
Typically these designs have windows that open on both sides. This allows maximum ventilation. One consideration within the garden window is water runoff. You need to take this into account otherwise the runoff water will cause damage to your wall.
Covering material options: Glass, as the greenhouse structure attaches to the home.
Ideal location: The greenhouse should ideally attach to the side of the home with a southern exposure.




Cold Frame
Cold Frames are used to extend the gardening season. The cold frame is the simplest and by far the cheapest greenhouse option. A cold frame is a square or rectangular bottomless structural cover with an angled transparent top. They protect your plants from excessively low temperatures, wind, snow and rain.
Covering material options: In true DIY spirit, anything goes (glass, plastic sheeting), the main requirement is that any covering should be able to be opened to allow heat ventilation.
Ideal location: Open field/backyard, with a south orientation for the tilted roof side.




Geodesic Dome
Geodesic dome greenhouses are beautiful and unique but they are also a great option for backyard food growing. The dome shape gives a large volume for a small surface area, with plenty of space inside for vertical growing. The shape also maximizes the sun exposure, so plants get the full benefit of the sun from all angles.
Covering material options: Plastic sheeting, shrink wrap, polycarbonate panels
Ideal location: Open field/backyard with any sun exposure




Conclusion
So there you have it. These are the most common types/styles of greenhouses. You could easily combine two or three of these type to create additional types. For example, you could take half a geodesic home and make it a lean-to attached to your garage. You could also take the cold frame and put it on top of a raised bed. Your options are as limitless as your imagination and gardening space.