How to Build a Greenhouse: 8 Step DIY Greenhouse Guide

A greenhouse is an enclosure with transparent walls and a roof that lets sunlight in, allowing gardeners to grow plants inside a controlled environment. Greenhouse designs can have any number of additions—including sun lamps, heating pads, air circulation, and water misters—to keep the plants inside happy.

There are many types of hobby greenhouses, including a cold frame, attached greenhouse, and freestanding greenhouse. Here are some of the most popular styles of greenhouse.

1. 1. Cold frame: Cold frames are the smallest and simplest of greenhouses, usually built as small boxes with hinged lids that gardeners can put plants inside. Cold frames are usually cheap to build or buy because they don’t require a heat source like other greenhouses. Home gardeners often use cold frames to protect their plants from the elements during the overwintering process, which is when cold-hardy plants are left in the ground to continue growing during winter months.
2. 2. Attached: Attached greenhouses are built up against a sturdy wall (usually the wall of a house) to anchor the structure. They can be as small as a window box or as large as the side of the building they’re attached to.
3. 3. Freestanding: Freestanding greenhouses are complete buildings, standing on their own and usually large enough for gardeners to enter. Since they need to be sturdy enough to stand alone, freestanding greenhouses are usually more expensive to buy or more complex to build.

There are a variety of methods for building a greenhouse. For example, you can construct a small DIY structure from greenhouse kits sold at your hardware store, or build your own free-standing or attached structure. How you plan to flame and cover your greenhouse will determine exactly which materials you’ll need. Here is a general overview of some materials that this home improvement project might require.

1. 1. Building materials: Choose a material to build the frame for your greenhouse based on your needs. Common materials used to frame a greenhouse are wood, PVC pipes, and aluminum. Consider how sturdy and durable you want your greenhouse to be depending on the challenges of your local climate. For instance, aluminum frames are sturdy and hold up well against rust and hold up well against precipitation.
2. 2. Cutting tools: Scissors are useful for cutting plastic sheeting, and a miter saw can come in handy for cutting wood to your desired dimensions. The specific material you choose for your own greenhouse will determine which cutting tools you’ll need exactly.
3. 3. Hardware: In order to build your greenhouse, you’ll need standard hardware tools such as power drills, a hammer, nails, screws, or any other material listed in your specific greenhouse plan.
4. 4. Accessories and extras: You’ll need a measuring tape, sealant, or glue to carry out this project. You may also need gravel if you choose to line your foundation out of gravel instead of poured concrete.
   
5. 5. Greenhouse coverings: Whatever material you choose to cover your greenhouse with will trap heat in your structure and encourage your plants to grow. With that in mind, you want to choose your covering materials wisely. Some common greenhouse coverings include glass, polycarbonate panels, or polyethylene sheeting (which is a type of plastic film).

There are many ways you can build a greenhouse depending on your available growing space and budget. To build a greenhouse for your garden and reap the benefits of a year-round growing season, follow these steps.

1. 1. Find a greenhouse plan. There are plenty of free plans available to help you build a number of greenhouses, from mini-greenhouses to barn greenhouses, to A-frames. Before you start working, make sure you have a plan to work off of that shows you how to make your chosen style of greenhouse.
2. 2. Choose a location. Pick a spot for your greenhouse that receives as much sun exposure as possible. Ensure that the longer sides of your structure face east and west so that your structure can absorb as much sunlight as possible. Avoid clusters of evergreen trees or other structures that may cast shadows on the structure. Choose a level spot that will allow for proper drainage.
3. 3. Measure your space. Use a tape measure to see just how much ground space you’ll need for your greenhouse. Ideally, you’ll have done this before you select a greenhouse plan, but it’s always helpful to double-check to see if you have enough room to execute your design.
4. 4. Get permission. Check with your local municipality to see if you’ll need a building permit or any other type of permission to add a greenhouse structure to your yard. Make sure that your construction is up to code and follows local ordinances if necessary.
5. 5. Determine your foundation. If the space you’re building your greenhouse on is uneven, you’ll have to lay a foundation in order to properly stabilize your structure and give it proper drainage. For cold-climate gardening, place the foundation beneath the frost line. If you choose not to dig a foundation, you can create a well-draining floor with gravel or landscaping fabric.
6. 6. Build your greenhouse frame. Build your greenhouse frame according to the directions included with your plan with your selected materials. Cut your wood pieces or plastic tubing to your desired lengths, and assemble them using the appropriate hardware, connectors, and adhesives.
7. 7. Cover your frame. You can use any combination of materials—including plastic sheeting, glass, or fiberglass— that you prefer for your DIY greenhouse project. Use caulk or sealant to secure your covering to your structure to properly insulate it.
8. 8. Include ventilation. Your greenhouse should be an atmosphere that mimics your plants’ natural growing environment, with enough air circulation and ventilation to encourage overheating, mold, or mildew to form inside your greenhouse. Install roof vents or circulation systems to keep your greenhouse properly aerated.

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