Building their own greenhouse was something Ken Southworth and his wife had talked about for years but just never got around to doing it. (Sound familiar?) But with the increasing cost and decreasing availability of fresh, healthy produce, Ken finally decided to get serious about his backyard project.
After doing a lot of research last winter on types of greenhouses, kit options, and contractor costs, Ken chose to design and build one himself. “I wanted to build a greenhouse that would be attached to our house so that we could have direct and easy access to it in all weather conditions without having to go outside,” Ken said. “Our house style, property layout, and solar orientation made a lean-to greenhouse the best solution for us.”
Typically, a lower cost alternative to a freestanding greenhouse, a lean-to greenhouse attaches directly to the exterior wall of an existing structure, such as a home or garage. This style greenhouse saves money on building materials as well as provides easier access to electricity, water, and heating sources. Ken explained it like this: “Since we heat our house with a wood boiler system, that made it easy to install a radiator/heat exchanger unit out there and tie it into our home system so that we will not have to rely solely on solar features.”
One of the critical decisions in building a greenhouse is choosing the right structure. The frame of Ken’s lean-to greenhouse is a custom steel kit designed and created by Worldwide Steel Buildings. Ken felt a steel frame would best suit his needs. “The end result is that I think our greenhouse can stand up to just about anything and will probably outlast us. We are very pleased with the results and glad that we went the route that we did.”
The other important building material consideration was the exterior covering. The three main types of greenhouse glazings are films, plastics, and glass with polycarbonate being considered one of the best options. Multiwall polycarbonate panels will maintain their high clarity and provide an outstanding balance of impact strength, and stiffness, excellent thermal insulation, UV protection, flame and condensation control, and long-term high light transmission.
“Multi-layered polycarbonate panels are cheaper, lighter, stronger, more thermally efficient, and easier to build with than glass, and will far outlast plastic films.” Ken said. “Unless you have an unlimited budget, multi-layered polycarbonate panels are really the only way to go for something that will be strong and good looking enough to attach to your house, especially for a DIY build.”
Because he was looking for a thermally efficient panel with light diffusing properties, Ken selected LEXAN™ THERMOCLEAR™ 15 Softlite 16mm polycarbonate for his greenhouse covering. The 100% diffusion feature of this high-performance panel is ideal for greenhouse applications. Plants benefit from high levels of light for growth while being protected from harsh, intense sunlight. The scattering of the light reaches both the top and bottom leaves resulting in faster, uniform growth, virtual elimination of shadows, brighter colors, and more usable energy to the plants.
Ken incorporated south-facing ‘window’ views using clear solid polycarbonate sheets that were the same thickness and width as the 16mm multiwall panels. “This allowed me to use the same H-channels that I used everywhere else. It also saved me from the extra work of framing in the windows and trying to make them weatherproof. We are very pleased with how they turned out. Everyone’s commented on how clear and nice the front windows are.”
Building your own greenhouse is a rewarding DIY project but does require some basic construction skills. “It’s not brain surgery but depending on your design, materials, and location it can be challenging without additional help or building experience.” Ken went on to say the panels’ light weight made them easy to handle and work with. “I was able to build our greenhouse all by myself with only occasional assistance from my wife when I needed an extra set of hands to hold something.”
A lean-to greenhouse is not just a place for growing veggies and flowers but an extension of one’s living space. It’s more like a garden sanctuary, doubling as a sunroom, an ‘outdoor’ dining area, or just a quiet place to relax and unwind. “We can’t wait to sit out there on cold, snowy winter days and be warm, surrounded by green and growing plants,” Ken said.
Are you considering building your own greenhouse? Here are a few of Ken’s tips: Do your research. Read everything you can find on greenhouses — styles, construction considerations, and materials. Then let your budget, your health, and your motivation dictate your choices.