There are 3 basic components in a greenhouse. You have the frame, the glazing material or covering and the greenhouse supplies.
If you are building your own frame, most people will choose wood due to the availability. You can use regular 2 x 4’s or treated lumber. With the new pressure treated lumber you do not have any issues with compatibility of the glazing materials. If you have access to aluminum or steel, they are also acceptable materials. Sometimes you may have a local sunroom company that will supply you with aluminum extrusions. Local welding shops may be willing to work with you on a steel frame.
There are a lot of different choices here and a lot of different price points. They are discussed starting with the least expensive and moving to the most expensive.
This is UV protected for longevity but the name is somewhat misleading. You may get 4 years out of it, but mostly this is referring to the length the UV protection is going to last.
This is basically 2 layers of film with a reinforced cord between them that is a rip stop feature. If the film is torn, it will not continue to tear past the cord. It will last much longer than the 4 year, 6 mil film.
This is a twinwall polyethylene material. The UV coating is not applied to the top of this material; rather it becomes part of the Solexx in manufacturing. It has a 10 year warranty and will also give you a much better insulation factor than either of the films. It is soft and may be rolled to be shipped UPS.
Polycarbonate is also a twinwall or multiwall material. There are many widths and specialty sheets available to reduce heat, etc. It is a rigid material and must be crated and shipped on via truck.
Another option is recycling old windows to build a greenhouse. This can be a fun project that allows the builder to create a greenhouse that is unique in style.
A greenhouse will not function properly without several supplies or accessories. The two most important ones are ventilation packages and heaters. The greenhouse will need some type of system to move hot air out in the summer months. This is typically done with roof vents, exhaust fans and intake shutters. A greenhouse will not maintain heat on its own during winter nights. There are some solar methods that do help retain heat in a greenhouse, but usually an actual heater is also needed to keep the heat at the desired temperatures. There are many other supplies for your greenhouse which may be added as needed such as, shade cloth, benches, misting systems, etc.
Don’t be intimidated by the thought of building your own greenhouse. There are many advantages to building your own over buying a greenhouse kit like designing it to fit your exact needs.
Tammy Wylie has been selling and installing greenhouses since 1993. She currently owns and operates two greenhouses, an 8 x 12 is used to overwinter plants and an 18 x 24 greenhouse is used to start vegetables, herbs and annual flowers. She also tests new products in this greenhouse and evaluates them for efficiency and user friendliness. She is the owner of Advance Greenhouses AdvanceGreenhouses.com.
Want more information? Read these articles:
A Guide to Planning and Building a Greenhouse
Greenhouse Construction: Planning for Snow Loads and Wind Loads
Greenhouse Space Saving Techniques
How Glass Works in Greenhouses
Understanding Foundations for Greenhouses