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Greenhouse Design 101: Choosing the Perfect Size and Shape for Your Garden

Having a greenhouse is a great way to grow plants in a controlled environment, and there are tons of choices on the market. Choosing which greenhouse design makes sense for you comes down to a number of factors such as the size, shape, and material you want.

The key to choosing the right greenhouse design is understanding your gardening needs, and how much effort you want to put into your greenhouse. Do you want to install a prefabricated one? Build your own? What works best in your yard?

Keep reading to understand what to consider when choosing the perfect greenhouse design.

A custom-built walk-in greenhouse in a garden.

What to Consider First

Before choosing the greenhouse design, you need to decide on the location of your structure. This determines how big of a greenhouse you can have, and what the right shape is. If you have a smaller yard, you’ll need a smaller greenhouse with taller walls to fit more shelves for plants.

If your yard is large, you may benefit from a shorter but wider greenhouse with lots of room to move. Consider if you want to bend down (a ground-level greenhouse design) or be able to stand up.

Windows opened to allow airflow in a greenhouse.

Sun exposure and proximity to water are two important considerations when planning the location of your greenhouse.

If you are able to, select an area near a hose connection so you can install a drip irrigation system for easy watering. Many drip irrigation systems will work but you’ll want to do your research. Read our blog post on 4 of the Best Drip Irrigation Systems for our recommendations.

Soil choice matters if you choose a ground-level greenhouse design. You can use a Plant Soil, Food and Fertilizer Guide to ensure the best planting medium.

Material and Style

When choosing material for your greenhouse design, you have to decide if you will build it yourself or buy a prefabricated version. Building it yourself has many benefits, such as being able to customize a greenhouse design that works best for your space, and a lower cost. But you’re responsible for creating a design that works!

A prefabricated greenhouse design allows for easier installation and less work, but it may be made of a material that is harder to work with such as metal. These kits also can come with plexiglass and features that are harder for most DIYers to install such as vented windows or built-in fans.

For a greenhouse design centered around DIY, the easiest materials to work with are wood and PVC pipe.

DIY – Wood

A backyard garden walk-in greenhouse.

Wood offers a more attractive and sturdy structure, which can be designed with a gable roof or slanted roof for good drainage in snow-prone climates.

Wood designs are generally made out of 2×4 lumber, which can be found at every major home improvement store. The walls can be made by wrapping greenhouse plastic film for good UV trapping. You can build a wood greenhouse to be the perfect size for you. If you need lanes that are big enough for your wheelbarrow and carts, you can design for that.

The largest drawback of this greenhouse design is the learning curve and time needed. You will need to be handy with construction tools and invest at least a full weekend to make a good-looking wood greenhouse.

Another drawback of the wood greenhouse design is that it can weather poorly. Wood will rot if not treated, and will eventually need replacing. Sealing off the greenhouse can be difficult with the sharp angles that normally go with this greenhouse design, so it takes a higher skill level.


A walk-in PVC hoop-style greenhouse.

Another DIY greenhouse design is the traditional hoop house made with plastic PVC pipe. This is a significantly easier project than the wood greenhouse design, but admittedly not as attractive in your yard.

The PVC option can be done quickly and cheaply, just with a drill and saw. You make a ground frame and bend the PVC to hoops that attach to either side of the frame. You can wrap this in the same greenhouse plastic you would use on a wood greenhouse design.

The major drawback of the hoop house, besides its looks, is the fact that it generally is going to be a ground-level greenhouse. That means that you won’t have the same ability to move around and store tools in it as with a wooden structure.

Hoop structures are easier to cover and prevent rain or snow from coming in, so the skill required is lower than the wood greenhouse design. They are also low-cost compared to every other greenhouse design option.

Prefabricated Kits

A large walk-in greenhouse.

Many retailers offer prefabricated kits which are perfect for most greenhouse designs. While they don’t offer the same flexibility and customization as a DIY solution, they’re easy to assemble, attractive-looking, and come with features that are harder to install yourself.

Prefabricated kits come in both metal and plastic. Metal kits are heavier and withstand harsher weather. Metal also has a more professional look and is considered higher quality than plastic kits.

The downside to a metal kit is twofold: cost and weight. Metal kits will be more expensive than wood, PVC, or plastic and will be much heavier, making them more difficult to assemble and move.

Plastic kits offer great durability to weather, but their lighter weight means they’re susceptible to wind. While not as sturdy as metal, they’re still rigid and make for a great long-term option. Plastic does have a cheaper look, however, and might be less attractive in your landscape.

Prefab Greenhouse Kit Recommendations

When choosing a prefabricated kit you have a number of options relative to size and shape. Many are perfect for the backyard like the Canopia by Palram which even has a small vent window. These kits are durable, come with more rigid plexiglass/plastic, and can offer you quick assembly relative to a DIY greenhouse design.

The prefabricated kits also come at a variety of price points and sizes. The Ohuhu Walk in Plant Greenhouse is a great example of an inexpensive prefab greenhouse that’s on the smaller end of greenhouses, yet still large enough to be a walk-in with shelf space.

If you want something bigger and sturdier, the Sellerwe Greenhouse offers a great middle-ground price point with a lot of features.

At the far end of the spectrum are the large hobby greenhouses like the Amerlife Greenhouse which features sliding doors and window vents. It looks great in a garden or yard setting and is very durable.

While many of the prefab kits are larger, there are some ground-level type greenhouses that are perfect for smaller-scale gardeners such as the Exaco Cold Frame Greenhouse. This greenhouse design allows for minimal impact to your yard space, and the flexibility of an easily moved solution.

Choosing the Size of Your Greenhouse

A walk-in PVC hoop greenhouse.

After you have determined which material you are using for your greenhouse, the next step is deciding on size. There are a few different considerations when thinking about size, and it will take some planning.

Sun Exposure

The first consideration is how much yard space you have that gets adequate sun necessary for growing plants and keeping them warm. The amount of sun your greenhouse receives will determine what kind of plants you can grow.

Number of Plants

The next step is determining how much space your plants will need. While this may seem like an obvious part of your greenhouse design, there are a number of factors that influence it. If you are going to use a ground-level greenhouse, you will have plenty of space to grow plants but less for tools and accessories like irrigation. You will also be limited to the actual footprint, as building up might not be viable.

If you are using a standing structure, you will want to determine how much shelf space or table space you will be able to fit. You can tier your plants on different levels, which also allows some to get more shade than others and increase the variety of plants you can grow in the greenhouse.

Looking to the Future

If you plan on growing your garden, it will require a larger greenhouse to meet your growing needs. So you’ll want to make sure you have space to expand your greenhouse in the future.

If you plan on diversifying the types of plants you have, you may want to consider a prefab option which will give you features such as vents or windows that open or fans to create airflow. A prefab is also great if you think you may move your greenhouse in the future as they come apart and can be rebuilt easily.

Frequently Asked Questions

Small greenhouses on raised gardening beds.

What shape or style of greenhouse is right for me?

It will depend on how much space you have for a greenhouse, how you’ll use it, how many plants you plan to grow, your budget, and if you want to do the work yourself. Consider the best footprint for your space, what material you want to use, and how much plant space you need to figure out what design is right for you.

What size greenhouse do I need?

This will depend largely on how much space you have to dedicate for a greenhouse, your number of plants, and any future expansion plans you may have.

Get Your Perfect Size and Shape Greenhouse

The interior of a walk-in greenhouse used for growing plants vertically.

When it comes to a greenhouse, there are many options. These range from DIY options to prefab kits. Depending on your space, level of comfort with DIY projects, and the type of material you want to use there are a number of options available to you.

The size and shape of a greenhouse will depend on the space available for the structure, sun exposure, number and types of plants you’ll grow, and how you want to access and use your greenhouse.

Don’t forget about other garden tools you might need! Check out our Garden Tools site for more information.

Want more garden content? Visit our gardening page for in-depth guides, explainer posts, and great ideas!