How much does it cost to build a greenhouse?

A greenhouse helps plants grow year-round. It protects them from the elements while allowing sunlight to warm the interior and helping plants grow. Greenhouses typically consist of a frame covered with a clear material. They can be simple or complex, have removable sheeting, fixed glass panels, or even heating, ventilation, and irrigation systems. They come in any size, from a tiny hoop greenhouse a few feet high to massive commercial structures.

With these variations comes a range of costs. The national average cost range to build a greenhouse is between $5,000 and $20,000, with most people paying around $10,000 for a backyard greenhouse measuring 10’ x 40’ with a gable roof. This project’s low cost is $1,000 for a hoop-style greenhouse measuring 10’ x 20’, while the high cost is a heated, ventilated, commercial-style greenhouse measuring 20’ x 100’ for $35,000.

Cost to Build a Greenhouse

Greenhouse Cost per Square Foot

The cost of a greenhouse per square foot varies depending on the type. The average cost range is $5 to $35 a square foot, but many things impact your total cost. The length of your greenhouse does not contribute nearly as much as the width and height. The greenhouse type and materials used also greatly impact your total costs. Adding shade, ventilation, irrigation, and heat increase your total costs as well.

Backyard or hobby greenhouses do not have to be large to be effective. Depending on what you want to do, you can build a simple hoop greenhouse covering your garden beds or an elaborate greenhouse with tables, storage areas, and a workspace.

The shape determines how much space you have. For example, A-frames do not have as much space as hoops, so they need to be larger to fit the same number of plants.

Greenhouse Cost by Type

The vast majority of greenhouses are freestanding. They are a separate, detached structure and can be placed anywhere. However, some hobby greenhouses can be built attached to your home. This is called a lean-to greenhouse, and it cuts down on some building costs. But it restricts the type of greenhouse you can choose because some of the least expensive styles and materials are not an option. Attached greenhouses can be built onto any structure, including your house, potting sheds, garages, and other outbuildings:

Freestanding Greenhouse

Freestanding greenhouses measuring 12’ x 12’ cost between $720 and $15,000 completely built. Most greenhouse types are freestanding. This includes simple hoop greenhouses to elaborate glass and steel structures. You have the most options for freestanding greenhouses in materials and style. This is because the cheapest materials include sheet plastic stretched over PVC hoops, which is not an option for something built onto the side of a home. Freestanding greenhouses can have floors, vents, heating, and other options, but these increase the project’s total cost.

Attached Greenhouse

Freestanding greenhouses measuring 12’ x 12’ cost between $720 and $15,000 completely built. Most greenhouse types are freestanding. This includes simple hoop greenhouses to elaborate glass and steel structures. You have the most options for freestanding greenhouses in materials and style. This is because the cheapest materials include sheet plastic stretched over PVC hoops, which is not an option for something built onto the side of a home. Freestanding greenhouses can have floors, vents, heating, and other options, but these increase the project’s total cost.

Attached greenhouses range from $1,440 and $15,000 for a 12’ x 12’ structure. There are significantly fewer options for an attached greenhouse than for freestanding. They must be more rigid and only have three sides. This means that you have fewer material costs for the structure, but you are confined to more expensive materials. Attached greenhouses do not get as much sunlight, so they may need more heating options than freestanding. They may be the best option if you are restricted on space and do not have room for a freestanding structure.

Greenhouse Construction Cost by Style

One of the most important considerations when building a greenhouse is the type and style. You want the greenhouse to effectively utilize the light for its position. If you live in an area that experiences considerable snowfall, choose a style that is not damaged by it:

Hoop Greenhouse

Hoop greenhouses cost between $5 and $10 a square foot on average. They are made of a series of half-hoops with the ends in the ground. The hoops are covered with sheet plastic, which helps keep the overall costs down. The hoop greenhouse can be as small or as large as you desire. They can be low to the ground or be large enough to walk through. The hoop structure’s shape lets snow and water easily slide from the top while allowing for good ventilation.

Gothic Arch Greenhouse

Gothic arch greenhouses average $10 to $15 a square foot. The Gothic Arch greenhouse design is a Quonset design, or hoop greenhouse, with a semicircular frame. The greenhouse is typically constructed using galvanized pipe. The total frame is circular in design but with a higher pitch (peak) than the traditional hoop. Plastic sheeting is usually used for the Gothic arch style. The simple design is ideal for shedding snow and rain. The only drawback is the low sidewall, which can limit grow space and restrict headroom.

Rooftop Greenhouse

The rooftop greenhouse ranges from $10 to $25 a square foot. These are not very common for residential use because they require a flat roof. However, if you live in a condo or other building with roof access, you can build onto the existing walls to create a greenhouse. These are simple structures, but they restrict the materials you can use. For example, they are most commonly made with a metal frame and solid glass or plastic panels. Using a rooftop greenhouse is a great way to get year-round gardens and vegetables in urban areas. They are very common in cities and commercial structures.

Lean-to Greenhouse

Lean-to greenhouses cost between $10 and $25 a square foot on average. A lean-to greenhouse shares the wall of a shed, garage, or house. In many cases, a lean-to greenhouse is an addition to the home and formed of glass. The lean-to greenhouse shares a wall with another structure, so the cost of construction is less than a stand-alone greenhouse. The temperature in a lean-to greenhouse is hard to regulate because its wall absorbs heat, but the greenhouse loses heat. A lean-to greenhouse should be south-facing.

Dome Greenhouse

Geodesic or dome greenhouses range from $10 to $25 a square foot. This is essentially a round greenhouse with a domed top. They can be made in many ways, from a rigid frame with glass or plastic panels to a PVC frame with stretched plastic sheeting over it. The dome’s shape is ideal for capturing light and heat. They also give you more interior room without taking up as much length or width outside. This style is usually kept small because the height and size increase with the diameter, making it difficult to build without dramatically increasing costs.

Pit Greenhouse

Pit greenhouses average $20 to $25 a square foot. A pit greenhouse is constructed by digging a hole in the dirt and building a greenhouse roof over the top. The benefit of a pit greenhouse is that the earthy floor maintains a 50-degree temperature year-round. The pit greenhouse stays about 10 degrees warmer than an above-ground greenhouse in the winter. In the summer, it stays warm, but it doesn’t require as much ventilation to avoid overheating as other greenhouses. They can have nearly any configuration over the pit, with hoops being the least expensive and rigid roofs being the most. Pit greenhouses need specific soil conditions to build. Having soil that is too sandy or loose could make the style too difficult to safely build.

A-Frame Greenhouse

The A-frame greenhouse costs between $25 and $35 a square foot to build. An A-frame is a common greenhouse structure. It is simple and requires only minimal building materials. It has a very high pitch roof, which comes down close to the ground, giving the building the shape of a letter A. In areas with snowfall, the snow often slides off the roof without causing damage. Air circulation within an A-frame greenhouse is often not ideal because of the corners. Situate the A-frame greenhouse to face south for best plant growth results.

Barn-Style Greenhouse

Barn-style greenhouses range from $25 to $35 a square foot. A barn-style greenhouse is often favored in areas where it gets hot during the summer months because the design features ground-level vents to keep plants cool and improve air circulation. With a barn-style greenhouse, there is an edge where the roof connects with the sidewalls, which are often slanted or vertical. The roof is sturdy and strong and is usually done in a gable style. There is more headroom in a barn-style greenhouse than an A-frame. Barn styles can have timber or steel frames.

Post and Rafter Greenhouse

Post and rafter greenhouses average $25 to $35 a square foot. This is a traditional “house” style greenhouse with a gable roof. The conventional style is extremely common. It is very strong because the roof is made of rafters, which lend strength to the structure. The design is top-heavy, so the base must be anchored or footed. This is a straightforward and simple design that is easy to construct. The long side walls maximize space for growing.

Sawtooth Greenhouse

Sawtooth greenhouses cost between $25 and $35 a square foot on average. This is a unique style with a primarily hoop frame, but with one straight section extending upward on one side. This section is ventilated, so you can more easily control the greenhouse’s temperature. It usually has a metal frame and can have plastic sheeting installed over the majority to keep costs down, but it requires moveable panels on the straight sections. You can also use solid panels throughout the greenhouse for a more cohesive design. This style offers a lot of headroom and good ventilation.

Solar Greenhouse

Solar greenhouses are the most expensive style, at $35 to $45 a square foot. The upper range assumes that you are adding insulation, HVAC systems, and water. The structure always faces south and has supported walls. The solid north wall helps maintain a consistent temperature in the greenhouse structure and provide strength. Such a greenhouse is always made from building materials that exceed 30 inches in thickness. The south wall is arch-shaped to absorb the sun’s rays. The peak is 12 to 18 inches tall. The material of the south side wall can always be rolled up for ventilation. Insulation pads constructed of straw are placed on the south side during the winter to hold in heat.

Greenhouse Pricing by Framing Material

The frame of your greenhouse can be made of several materials. Either metal or PVC is the most common, but some frames can be made of wood, particularly the bottom sections where the frame begins. Depending on the type, you may need more or less framing material. Some types like the hoop do not require much framing, while the post and rafter requires more:

Greenhouse PVC Framing

PVC framing is the least expensive, costing between $0.50 and $2 a linear foot. This is a good choice for hoop-style and other smaller greenhouses. It is lightweight and easily moved. PVC is also good for DIY greenhouses and those on a budget. It is more limited in scope than some other frames. For example, it is most frequently used with plastic sheeting rather than glass or rigid plastic paneling. PVC is readily available as kits and standard framing material.

Greenhouse Aluminum Framing

Aluminum framing ranges from $1 to $2 a linear foot. This is another very lightweight material that can be used for framing. It is more versatile than PVC, so you can build many more designs. It can be used with plastic sheeting or glass or plastic panels. This provides the structure with more options. While lightweight, aluminum is sturdy and long-lasting. The biggest issue is that it is easily dented, so it is not the best choice for some climates or busy yards.

Greenhouse Wood Framing

Wood framing for greenhouses costs between $1 and $2 a linear foot. This is not a common material for greenhouses. It is more limited in use and may not hold up as well in humidity. However, it can be combined with PVC, such as creating the ground frame of a hoop-style greenhouse. It can also construct some simple frames. It can be used with panels and sheet plastic, depending on how it is used.

Greenhouse Steel Framing

Steel framing for greenhouses average $2.50 to $3 a linear foot. This is one of the most common materials for greenhouse use. It is stronger than aluminum and can last longer without issue. It can also be formed into many shapes and styles to create nearly any type you desire. Choose galvanized steel because it holds up better in the humidity and lasts the longest.

Greenhouse Glazing Cost by Type

Glazing refers to the material covering a greenhouse. It lets sunlight into the structure while protecting the plants. Glazing also helps control the temperature and humidity. The type depends on the greenhouse’s location and the crops you are cultivating. Another factor to consider is the material’s longevity. Some glazing lasts a lifetime and others only a season or two. Many people want opaque glass for privacy, and others like translucent material to see out and in.

Polyethylene Greenhouse Cover

Polyethylene greenhouse covering is the least expensive option at $0.10 to $0.50 a square foot. This is the flexible, tough plastic sheeting used in most low-cost greenhouses. You can use this material for hoop, gothic domed, some pit, and other round greenhouses. It is easy to use and install, and you can lift or roll it up to ventilate. In most cases, you do not even need a door with this cover because it can be pulled across the openings. This type is not as long-lasting as others, so you may want to replace it eventually.

Corrugated Fiberglass Greenhouse

Corrugated fiberglass panels for greenhouses average $1 to $2 a square foot. These large panels typically cover about 16 sq.ft. at a time. These are clear panels that are usually two-sided, with some space between them. This makes them better at insulating than the other types. You are less likely to need additional insulation, depending on your climate and how often you intend to use the space. These can work in many structures and be fixed or ventilated as needed.

Polycarbonate Greenhouse

Polycarbonate greenhouse glazing ranges from $1.60 to $3 a square foot on average. This is the most common type of glazing used today. It is thick, durable, and can include an air layer of insulation. It can be tinted for shade or completely clear so that the sun comes in. Most greenhouse kits today use polycarbonate glazing as part of their structure. The material is not nearly as delicate as glass, so it lasts considerably longer.

Greenhouse Glass Glazing

Glass for greenhouse glazing costs between $2.50 and $3.50 a square foot. This is the most expensive material for greenhouses. Like the glass in your home windows, it can be single or double paned for better insulation. It is also fairly fragile and more easily broken, so it does not last as long as polycarbonate. However, glass is the most striking greenhouse material. Its crystal clarity creates a beautiful design with more curb appeal and potential value.

Greenhouse Foundation and Flooring

Not every greenhouse needs a foundation. Some greenhouses can be built directly over a garden bed. However, some people choose to use a material for a foundation or floor. This can be a concrete pad or pavers as for a patio. If you use a solid concrete slab, you must include drainage on the floor.

The average cost of a concrete slab is between $90 and $100 a cubic yard. The cost of patio pavers is between $1 a square foot for gravel and $25 a square foot for stone. Anything you put down must withstand the heat and humidity and allow for good drainage.

Greenhouse Insulation Cost by Type

Depending on where you live and the glazing type, you may want to add insulation to your greenhouse. This is not strictly necessary, and many greenhouses do not use any. However, if you want to use your greenhouse year-round, you may want to consider insulation. There are different types of insulation, depending on your goals and greenhouse.

Thermal Screen Greenhouse

Thermal screens for greenhouses cost between $1.50 and $4 a square foot on average. This is a layer of material that you can add in the winter. It is removable and repositionable to get the best results for your climate. Thermal screens can be made of different materials. Some are flexible fabric, while others may be rigid panels that you can place over your glazing. Their cost range reflects the many options. They also have different insulating values, depending on the brand and style.

Base Cladding

Base cladding averages $1.60 to $3 a square foot. This cladding is installed at the base row of glazing. It helps insulate at the ground level. You use this cladding in place of or over a glass or thin plastic panel. It is not for use with plastic sheeting. Most are made to be put on in the winter and taken off in the summer. You can use polycarbonate glazing for insulation.

Double-Pane Glass Greenhouse

Double-paned glass ranges from $2.50 to $3.50 a square foot on average. If you plan on using glass and do not want to worry about additional insulation, use double glazing. You need to install this when the greenhouse is built. This is not as effective as polycarbonate or adding additional insulation. However, it is a good choice for moderate climates where additional insulation is not necessary. It is also a good way of maintaining your greenhouse’s appearance long term.

Greenhouse Bubble Wrap

Greenhouse bubble wrap or bubble plastic costs between $2.60 and $3 a square foot. This is a thick sheeting of plastic. Air is caught between the two layers in large bubbles. This air helps insulate the greenhouse. You can use this to replace plastic sheeting on hoop greenhouses in the winter. You can also add this on top of another glazing for other greenhouses. This way, you can gain the insulation you need when you need it and easily remove it when the weather warms up.

Greenhouse Door Cost by Type

Not all greenhouses require doors. However, any type with a rigid frame and glazing needs a door to control the temperature properly year-round. Depending on the greenhouse and climate, you have several choices for doors.

Labor Cost to Build a Greenhouse

For most greenhouses, the total cost of building and materials is quoted together by the square foot. However, you can also break down the labor.

If the site where the greenhouse is located requires excavation to level the area or remove underbrush, you must hire an excavator. The cost of excavations depends on the land. Flat-to-moderately sloped land with light-to- medium vegetation normally costs $3 to $6 per sq.ft. Sloped or hilly land with heavy vegetation averages $15 or more per sq.ft.

The price to hire a landscaping contractor to construct the greenhouse averages $50 to $100 per hour for labor to frame the greenhouse and apply the glazing. Landscaping contractors might charge by the hour or project.

Many people opt to hire a handyman to construct the structure and apply the glazing. A handyman charges $60 to $90 per hour, or they charge by the job.

While you can hand-water your plants, many people also choose to run water to their greenhouse. Your landscaper can install this for $50 to $100 an hour. If desired, you can also have an electrician run a line to your greenhouse for power tools or lights for $40 to $100 an hour.

Average Greenhouse Cost by Heating Method

Technically, a greenhouse is only heated by the sun, and a hothouse is heated using artificial sources. However, many people with a greenhouse want to heat their greenhouse with an artificial heat source if they live in a region that experiences particularly cold winters. Another consideration is the type of plants you grow. Some rooted and leafy vegetables grow in an unheated greenhouse if they are protected from the snow. However, if you grow tropical or warm-season vegetables, you need a heated greenhouse.

Unheated Greenhouse

Unheated greenhouses cost between $5 and $35 a square foot on average to build. Depending on where you live, how much sun the area gets, and the glazing and insulation, heat may not be necessary. This is purely a personal preference. Most people choose not to heat their greenhouses and let the sun do the work. In many areas, the greenhouse stays warm even in winter. You can add heat later in some instances if you start using your greenhouse regularly.

Heated Greenhouse

Heated greenhouses cost more at $35 to $45 a square foot. A heated greenhouse lets you grow year-round. This is not necessary for many climates, but if you live in a northern area that sees cold winters, heating your greenhouse can make a big difference. You can add radiant heaters fueled by electricity, gas, or propane and space heaters. Radiant heaters can be installed along the greenhouse walls and heat the plants directly rather than the air, making them very efficient. If you choose a heated greenhouse, most of the added costs come from the insulation. The greenhouse needs to be airtight to prevent thermal transfer and maintain the heat.

Pros and Cons of a Greenhouse

There are many benefits to building a greenhouse. There are also a few potential drawbacks. Consider each before building to make sure you get the greenhouse that is best for you.

Greenhouses allow you to grow plants year-round. They also give you a place to get plants started earlier in the season than outside. They help you grow more sensitive plants or even types of plants that do not do well in your climate.

A greenhouse can be expensive to build, so get the use out of it that you intend. They can increase energy costs, particularly if you need to add water, electricity, and heat. They can also take up valuable yard space. If space is at a premium, a greenhouse could take up room for outdoor gardens.

Greenhouse Maintenance Cost

Greenhouses need regular maintenance to make sure that everything growing inside continues to do well long-term. This includes regularly removing everything from the inside, washing, and sanitizing the interior. You should also inspect the glazing yearly and replace any cracked or broken panes as needed. If you choose to insulate for the winter, you have additional costs related to adding the insulation and storing it for the summer.

Overall, most people find that they spend less than $100 yearly on average maintaining their greenhouse.

Commercial Greenhouse Construction Costs per Square Foot

Commercial greenhouses cost around $25 to $35 a square foot on average - or at the upper end of the spectrum for residential or hobby greenhouses. They can be made in a large hoop or Quonset style at a lower cost or made using thicker materials at a higher cost. Typically, what differentiates a commercial greenhouse from a hobby greenhouse is size. Commercial greenhouses tend to be much larger and include more heating, ventilation, and insulation than average hobby greenhouses.

Enhancement and Improvement Costs

Shelving and Benches

You can place shelving in your greenhouse to hold potted plants and supplies. Some people also use them for potting. The average price of shelving is $10 to $50, depending on the size and type. Many people also include tables or benches to hold more pots or make a comfortable seat to work. These cost between $50 to $100 on average, and most greenhouses include several of each, depending on the size and setup.

Watering/Misting System

If you choose not to hand water, you can have water or mist run to your greenhouse to make it easier to care for your plants. A watering/misting system can be installed by a landscaper. Landscapers charge $50 to $100 per hour for labor. The system keeps the soil moist without flooding it. The average cost to install a water/mist system in a greenhouse is $500 to $1,000.

Rainwater Guttering

A rainwater guttering system catches rain that you can reuse to irrigate. The gutter system also keeps water from running down the sides of your greenhouse and saturating the soil. You can have the same type and style of gutters installed as on your home. The difference is that most greenhouses do not have any fascia to attach to, so clips or hangers must be used. The average cost of gutters is around $3 to $30 a linear foot installed.

CTT and Security Lights

You might want to have CTT and security lights installed around your greenhouse because some crops are valuable. They can easily be stolen without the protection of a security system. Electricians charge $40 to $100 per hour to install lighting. You can also choose to install solar lights around the greenhouse. These turn on with movement and require no electricity, making them a safe and energy-efficient option for many areas. If you are concerned, install cameras for around $600 on average.

Additional Considerations and Costs

• Depending on where you live, you might be required to purchase a zoning and building permit. The cost of permits averages $450 to $600.

• Building a greenhouse can be a DIY project. Kits are sold that provide instructions on how to build the greenhouse. You can also design your own greenhouse if you have a basic understanding of carpentry. However, it is advised that you hire a skilled landscaping contractor who specializes in greenhouses. A 6’ x 12’ greenhouse kit with polycarbonate panels and a wood frame averages $2,000.

• When hiring a contractor, always research the company on the internet, ask for references, verify their license and insurance, request a written permit, and check the contractor with the Better Business Bureau. Also, obtain more than one quote from various contractors. Never choose the lowest or highest, but instead opt for the middle-priced quote.

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