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The Ultimate Greenhouse Buying Guide: Everything you need to know before buying a greenhouse

Are you thinking about buying a greenhouse? Don't worry, this guide will teach you everything you need to know before you make a purchase. 

Don't waste any more time, we have the best greenhouse buying guide in the market. 

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Choosing The Right Size 

One of the first things you should consider before buying a greenhouse is how large you want your greenhouse. To determine the size of the greenhouse, you need to consider how much space you have. 

As a rule of thumb, you should always choose a size that is larger than the current space you need. Oftentimes, greenhouse owners choose a size they need at the moment, but in a short period, your plants will likely grow, your gardening will expand and you will need more space. 

As a result, you should consider buying a greenhouse that is 6 - 12 feet larger than you expect you need. This will give you room to grow into the space. 

Also, when choosing the size of your greenhouse, you should consider how much you want to grow or how much you hope to grow. If you are looking only to grow several plants, then a smaller greenhouse is ideal. On the other hand, if you want to grow a whole garden of multiple plants, you will likely need a larger greenhouse. 

For hobby or smaller growers, the standard size is 6’ x 8’ or 8’ x 8’. If you are a more experienced gardener and grow much more plants, a more common size is 8’ x 16’, 8’ x 20’, or 8’ x 24’. On the other hand, if you are looking to scale your growing, you should consider a larger greenhouse, such as those larger than 10 feet wide and 15 feet in length. 



There are many different shapes of a greenhouse that you can choose from. When considering the shape of your greenhouse, you should consider your aesthetic preference, weather conditions, the type of plants and flowers you will be growing, and the size of the greenhouse that you want. 

Another important thing to consider when choosing the shape of your greenhouse is the type of weather you will be experiencing. Certain shapes are better suited for heavy snow, rain, or high winds, such as gothic arc and tunnel greenhouses. 

Some of the most popular greenhouses shapes are gable, tunnel, gothic arc, and lean-to. These structures are commonly found as greenhouse kits and are easy to construct. 

Frame Material 

The 4 common frame materials for greenhouses are aluminum, steel, wood, and PVC. It's important to note that the frame material has a huge impact on the durability of your greenhouse. 

  • Aluminum: Aluminum is the most common frame material used in greenhouse kits. The reason is that aluminum is lightweight, durable, and cost-effective. Aluminum frames provide you with a high level of durability with frames that can withstand high-wind and large snow loads. Some of the strongest aluminum frames can withstand up to 75 MPH and up 32 pounds per square foot. 
  • Steel: Steel is one of the strongest frame materials that a greenhouse can have. While steel is highly durable, it's heavier and more costly than an aluminum frame. A steel frame material is ideal if you are looking for maximum durability, and your greenhouse will endure harsh weather conditions. 
  • Wood: Wood is another common frame material. Wood is a natural alternative to metal frames. A wood frame has an elegant finish that is easy to repair but also very durable. When choosing a wood for your frame, your choice of wood is important. Woods such as redwood and cedar are durable, heavy-duty, moisture resistant, and rot resistance. When reinforced with metal plates, wood greenhouses can be just as durable as metal greenhouses. 
  • PVC / Plastic: PVC or plastic frames are the most cost-effective option for a greenhouse. These frames don’t offer much durability and are often used in areas that don’t experience harsh weather conditions. Plastic frames are often combined with lightweight and inexpensive wall and panel materials. PVC frames are a great option if you are looking for a large greenhouse at a fraction of the cost. 

Glazing / Panel Material 

Greenhouse glaznig or panel material is the material that a greenhouse will use on its walls and roof. This material is very important because it will impact the durability and light transmission of a greenhouse. 

The three most common glazing used on greenhouse kits are polycarbonate, glass, and polyethylene. 


The most common panel material used by on greenhouse kits is polycarbonate. The main reason is that polycarbonate is durable, lightweight, and inexpensive compared to other durable alternatives. Another major advantage is that they don’t discolor and they are shatter resistant making then durable and very safe.

Polycarbonate panels are versatile because they come in different thicknesses and transparency. This means that you can find everything from slightly durable with single pane 4mm polycarbonate panels or highly durable with 10mm triple-wall polycarbonate panels.  

Prices for polycarboante panels can varry depending on their thickness but on average - polycarbonate is less expensive than a glass with similar thickness, durability, and light transmission. 

Below is a guide on polycarbonate panel thickness and the level of durability. 

Degree of Heavy Duty

Polycarbonate Panels


4mm Twin-Wall Polycarbonate


8mm twin-wall polycarbonate


10mm Triple-wall polycarbonate


The second most popular type of panel material used in greenhouses is tempered glass. You should always purchase a glass greenhouse that uses tempered glass compared to any other glass, especially annealed glass. 

Tempered glass is approximately four times stronger than other types of glass. In addition, tempered glass is designed not to shatter into large, jagged pieces of glass. Instead, tempered glass breaks into small, relatively harmless pieces. 

This makes tempered glass more durable and safer than other types of glass.

Its important to note that tempered glass is typically heavier and more expensive than other alternatives. Similar to polycarbonate greenhouse kits come with tempered glass in different thicknesses. 

The most common glass included in greenhouse kits is either double pane 3mm or 4mm tempered glass. This is a highly durable glass than can withstand and provide insulation in harsh weather conditions. 


Polyethylene is a lost cost glazing option for greenhouses. Polyethylene is a flexible and durable plastic that can be used as a glazing option for greenhouses. 

Polyethylene is a great greenhouse glazing option because it comes in large sheet sizes, easy to install, and has variable thickness and light transmission.

The one major disadvantage of polyethylene is that its not durable compared to other glazing options. It does not protect your greenhouse against heavy snow or strong winds. 

Its important to note that polyethylene comes in a variety of thicknesses. Depending on your needs you choose a thickness that works best for you. Often times, polyethylene greenhouses will have more durable glazing on their end wells such as polycarbonate, glass, or metal and then use polyethelene as their roof and side walls. 

Polyethylene is a great option in several scenarios: 

  1. You are looking to build a inexpensive greenhouse 
  2. You greenhouse is in a region that does not experience harsh weather conditions or your plants will not be inside the greenhouse during harsh conditions
  3. You are looking to build a large greenhouse at a fraction of the cost 

There are a few key benefits that polyethylene offers as a glazing option: 

  • Lightweight 
  • Inexpensive 
  • Offers temperature control
  • Reduces nightime heat loss
  • Reduces daytime heat absorption 
  • UV-ray protection 

Panel Thickness 

The panel thickness is an important factor when buying a greenhouse. The panel thickness refers to how thick the glazing on your greenhouse is. 

The thickness of your glazing is important because it determine the durability, insulating ability of your greenhouse glazing. 

In general, for glass and polycarbonate the thicker your greenhouse glazing the more durable your greenhouse will be. 

In addition, the thicker your greenhouse glazing the better the inulsating ability. Insulation is important because it helps with temperature control. Glazing with a higher insulating ability does two things it allows for less heat loss at night and also allows for better temperature control during the day. 

Below is a guide for different insulation rating for different materials. The higher the R-value the more insulation it offers. 

Below are some guidelines for choosing a glazing thickness: 

Durability & Insulating Ability

Polycarbonate Panels

Glass Panels



4mm Twin-Wall Polycarbonate

4mm double-pane tempered glass

4mm Polyethylene Single Film


8mm twin-wall polycarbonate

6mm double-pane tempered glass

5mm Polyethylene Single Film


10mm Triple-wall polycarbonate

8mm triple-pane tempered glass

6mm Polyethylene Single Film

*It’s important to note that polyethylene is a plastic and is hard to compare to polycarbonate and glass glazing options. While 4mm polycarbonate and 4mm tempered glass but it’s not comparable to a 4mm polyethylene film. 

Freestanding or Attached / Lean-To 

One of the most basic options you need to decide when choosing the design of your greenhouse is weather its freestanding or attached. 

Freestanding greenhouses typically have four walls and they don’t rely on an external structure for support. The major benefit of freestanding greenhouses is that they come in much more shapes and sizes compared to attached greenhouses. 

One of the major benefits of a freestanding greenhouse is that they are easier to find in a kit option. The downside is that they are typically more expensive than an attached greenhouse with the same size and features. 

Attached or lean-to greenhouses rely on another structure such as a house or other outdoor structure  for structural support. This typidcally means that lean to greenhouses only come with three walls and the fourth wall from another structure. 

One major benefit of attached greenhouses is that they are less expensive than freestanding greenhouses. A disadvantage is that 



There you have it, everything you need to know before buying a greenhouse. Now you are well prepared to research and buy a greenhouse that best fits tyour needs and will last a lifetime. 

Don't waste anymore time. You can now choose and buy a greenhouse confidently.