One thing we quickly discovered, is that there are several types of greenhouses or greenhouse designs and much of the terminology seems to be confused or interchangeable. A Hoop House or Low Tunnel described at one place looks an awful lot like a Cold Frame being sold at another place. Below we have listed the different types of greenhouses you can build, approximate costs and descriptions of each kind.
Common Greenhouse Designs and Estimated Costs (per square foot) for Small Backyard Greenhouses:
- Cold Frame/Hot Box – $0.50-$1.00/sq ft – total DIY cost for our project = $25-$50
- Row Cover – $0.20-$0.50/sq ft – total DIY cost for our project = $10-$25
- Low Tunnel or Hoop House – $1.00-$2.00/sq ft – total DIY cost for our project = $50-$100
- High Tunnel – $1.00-$5.00/sq ft – total DIY cost for our project = $50-$250
- True Greenhouse – $10.34-$54.39/sq ft – total cost for commercially available kits = $517 -$2,719 for a stand alone structure with glass or hard polycarbonate panels – no foundation included
Cold Frame or Hot Box
A traditional cold frame, also called a hot box was a simple wooden box with a hinged glass top. People used to salvage old doors and windows and build the frame to fit the window. Some small commercially available “plastic cubes” are also called cold frames. The cold frame/hot box could be a simple as a small raised bed covered with glass or even plastic sheeting or it could actually have glass sides like a miniature greenhouse and be several feet tall. A cold frame could be permanently left in one place, or be moved from place to place if small enough.
Row covers are very low, covered tunnels made from metal or plastic hoops that support a spun fabric or plastic cover. Floating row covers refer to covers that are made from light weight material that is temporarily laid over crops like frost blankets. A row cover is only high enough to cover the plants in one or two rows. Except for an irrigation system, row covers, would usually usually include any additional technology. Row Covers are temporary and can quickly be installed or removed.
Low Tunnel or Hoop House
Low tunnels and hoop houses are apparently different names to describe a design that is similar to a row cover, except that the hoops span a larger height and width. Tunnels or hoop houses normally do not include much technology except for irrigation. Think of a low tunnel as a long, extended hoop house. Because of it’s length, a low tunnel would be more of a permanent installation, while a hoop house could be either permanently or temporarily installed.
Examples of Floating Row Cover and How To Build a Low Tunnel Frame
The high tunnel design is similar to a Low Tunnel, except the walls are built higher to provide more height inside for moving equipment and for better air circulation. High Tunnels usually begin to incorporate more technology into the system and are normally considered permanent structures.
What we typically think of as a greenhouse is usually a rectangular shaped house (Gable) with glass or other rigid panels on the walls and the roof. A true greenhouse is tall enough for people to move around easily and also allows for good air circulation. Greenhouses usually include a high degree of automated technology. Greenhouses designs can also be Skillion shaped (Roof high on one end to provide for ventilation). A row of connected skillion greenhouses are referred to as a Saw-tooth greenhouse design. Most backyard greenhouses are referred to as hobby greenhouses.
Question: What kind of greenhouse design do you want to build and why? Do you have your own unique design in mind? Modifications? Let us know below.