I get this question a lot. What is the difference between a glass greenhouse and a polycarbonate greenhouse. I am going to assume that the frames are basically the same, so the biggest difference will be in the glazing material.
Glass greenhouses will be more expensive than a polycarbonate greenhouse. Especially with a curved eave. The glass is all tempered (safety) glass, even the curve. The curved tempered glass is more expensive than doing a curved polycarbonate. The twinwall polycarbonate is flexible enough that it is bent right onsite as you are installing the kit. There are no special tools or processes needed to do this. You just simply bend it over into the curved frame and attach it.
Looks are another obvious difference. The glass greenhouse will have more of a timeless look to it. I suppose if you want to use the word “fancier” that could even be applied. Just in looks, not in function. A lot of people don’t like the polycarbonate glazed greenhouse as it will be translucent rather than transparent. It will not be like looking through a window like the glass greenhouse will. Twinwall polycarbonate is made up of 2 sheets, an interior and an exterior. These sheets are both clear and would look much like looking through a window if you peeled the walls apart. Multiwall polycarbonate is much like looking down the end of a cardboard box. You will have the exterior and the interior sheet with a rib in between them. The rib will run straight between the 2 sheets, not curvy like in a cardboard box. This rib is what distorts your view. You can see color in a polycarbonate greenhouse, just not a clear form.
The glass greenhouse will not be as well insulated as the polycarbonate greenhouse. A single glass greenhouse will have an R value of approximately 0.95. A 6mm twinwall polycarbonate greenhouse will have an R value of around 1.6. This means that if you have the same size single glass greenhouse and polycarbonate greenhouse in the same location, trying to heat it to the same temperature, the glass greenhouse will cost you more to heat. It seems from the difference in the R value that it would be about twice as much. That is not the case. There is a formula that uses the size of the greenhouse, the difference in the temperature inside and outside the greenhouse, and the glazing material. If this is a consideration in your instance, the best way to determine how many BTU’s you will need is to actually do the calculations.
Breakage is another issue. Tempered glass will break if it is hit in the right manner. There is just no way around it. But, it is tougher than regular float glass, and it will shatter into small pieces, so safety is not a concern. Polycarbonate has a 10 year warranty against hail damage. It is a very tough material. It will not break like the glass.
Lifetime of the glazing material is the last issue I will discuss. Glass will pretty much last forever unless it is broken. Polycarbonate generally has a warranty that the light transmission will not vary more than a specified number in 10 years. This is just a fancy way of saying that it will not turn yellow or get brittle. Some of the manufacturers have extended their warranties to 15 and even 20 years. I have personally seen sheets that were 15 years old and still in use. They looked just fine. I have had reports back of 20 year lifetime on the material.
Glass greenhouses vs polycarbonate greenhouses? What is the conclusion. They both have their benefits, it just depends on which fits best into your needs. The best decision is to make sure to get a greenhouse, no matter what type. It will give you hours of enjoyment, produce food for your family, protect your orchids, and be the envy of your friends and neighbors.
I received an email yesterday with this in the subject line. STILL a very happy customer!!! Lynne and Mike were kind enough to share a few words about their tempered glass shed style attached greenhouse. They purchase their Acadian Lean To in 2007. It is always nice to hear that people are happy with their purchases. Following is the email.
Just wanted to reach out and express our complete satisfaction with your product. It has been ten years now and we enjoy the greenhouse as much now as when it was new. Many enjoyable snow storms and rainy afternoons. It has endured the severity of the east coast temperature extremes and provides sanctuary to our plants without fail. Can’t thank you enough for all of your customer service during the purchase and shipping process. I wish all establishments had your dedication to customer satisfaction. Thank you so much,Mike and Lynn Gaither
With the long holiday weekend upon us, there is not a better time to visit a local display greenhouse. I have several favorites. I love to go to Bellingrath Gardens in Alabama. They have a beautiful conservatory. City gardens in New Orleans also has an excellent conservatory. Even the small town of Monroe, LA has the Biedenharn with a beautiful conservatory. If you have a little more time and can take a trip the Biltmore in NC will also take your breath away. Also, Calloway Gardens in GA has a conservatory with butterflies and plants. These are all probably within an 8 hour drive of our location. You will probably not have to go far to find several in your area as well. Take a young gardener along and inspire them. You will find many styles and sizes of conservatories and greenhouses to explore. This article is about a couple of photographers who have started on a quest to explore greenhouses in far away places. I am totally envious of them.
Magnus Edmondson and India Hobson’s greenhouse quest began in Oxford, England, at the Botanic Garden, on a Sunday morning. “We were the only people there, and it was so incredibly quiet,” they write. The only sounds were “gasps of wonderment” and the “occasional sigh.” From there, Edmondson and Hobson, photographers based in Sheffield, were hooked. They began what they call “a self-initiated Greenhouse Tour of the World”—they find, explore, and photograph greenhouses, potting sheds, polytunnels, conservatories, and other indoor spaces made by humans, for plants.
You have dreamed for years about owning a greenhouse. Now the time has come. What size do you get? Most people have problems making this decision. I think the best way to start is to think about how you are going to use the greenhouse. If you have plants that you are going to overwinter, I suggest laying them out in your yard in a configuration similar to what you will do in your greenhouse. Then you just measure outside the plants and voila, you have the answer to this question. If you are growing in raised beds, decide what size beds you will have and draw them out on a piece of paper allowing for adequate walkways. The same would apply if you are using systems such as hydroponic systems. Find out their size and draw them in a configuration you like on a piece of paper. When considering raised beds and/or greenhouse staging, you need to be sure that they are not so wide that you are unable to maintain the outside plants properly. I suggest not using any wider than a 3′ bench for benching that will be against a wall. If you are using a bench in the center aisle, it is OK to use a 4′ wide bench. Keep in mind that most of us will be comfortable with a 3′ wide walkway, so be sure to draw them in as well. I do not recommend even trying to put a center bench in a 12′ greenhouse. Lots of people try and I don’t think they are too happy with the outcome. If I would do this, I would only use 2′ wide benches to ensure adequate walkways. I would get at least a 16′ width for a center bench. The best thing to remember is that we are all collectors. You know, that perfect color plant, an unusual vegetable, etc. Don’t buy a greenhouse you will be crammed into with your current plants. Always allow a little room for expansion. If you need any help with this decision, feel free to contact us at Advance Greenhouses.