Building or installing a greenhouse costs $5 to $30 per square foot on average for labor and materials, or $2,500 to $15,000 total for a 500-square-foot backyard greenhouse. The total cost depends on the greenhouse size, type, materials, and whether you choose a prefab greenhouse or hire a professional to design and construct a custom-built structure.

• A hoop house style greenhouse costs $5 to $10 per square foot to build, making it the most budget-friendly option. This style is made with a row of half-hoop arches covered with plastic sheeting and works well in wet climates.
• A geodesic or dome style greenhouse costs $10 to $25 per square foot and is ideal for small spaces.
• An A-frame greenhouse costs $25 to $35 per square foot to build and is ideal for snowy and rainy climates.
• If your space is limited, consider a kitchen greenhouse window instead. A kitchen garden window costs $1,500 to $5,000 installed and is typically 24"x24".

Greenhouse maintenance costs can range from $10 to $40 per month for a small backyard greenhouse in a moderate climate to $3,000+ per month for a large, climate-controlled greenhouse in an extreme-weather-prone region.

Common repairs include:

• Fixing or replacing damaged plastic sheeting, glass, polycarbonate, or fiberglass panels
• Periodically resealing a wood-framed greenhouse to prevent moisture damage.

Besides occasional repairs, ongoing operational and maintenance costs may include:

• Water – The amount of water you need depends on the climate and the types of plants you grow.
• Electricity – Some greenhouses have electrical costs from lighting, ventilation fans, heaters, HVAC systems, and automated watering systems.
• Pest control – Hiring a professional pest control service costs $80 to $120 per visit.

Building a greenhouse can take a few days to several weeks, depending on the size and design. A simple or prefab greenhouse will take less time to build than a greenhouse that is custom built from the ground up. The size and experience level of the building crew also affect the building timeline.

The lifespan of a greenhouse is 3 to 60 years. This extremely broad range is because a greenhouse's longevity greatly depends on the materials used, the quality of the construction, and the climate. Some materials may wear out or need replacing faster than others. You can extend your greenhouse's life by keeping it clean and well ventilated and regularly checking it for cracks, leaks, and mold.

• Wood- and steel-framed greenhouses last 30 to 60+ years.
• Glass greenhouses last 30 to 40 years.
• Polycarbonate panels last 10 to 15 years.
• PVC and plastic sheets last 3 to 5+ years.

You may need a permit to build a greenhouse, depending on its location and size. Contact your local government authorities to confirm the current building and zoning regulations before building your greenhouse.

Follow these guidelines to help you choose the best greenhouse installers near you:

• Compare 3+ estimates from licensed and insured greenhouse building companies.
• Browse the greenhouse builder reviews on HomeGuide and Google.
• Go with a company that has been in business for 5+ years.
• Get a detailed contract and warranty in writing before the work begins.
• Avoid the companies with the cheapest quotes as this may indicate low-quality work.
• Avoid making a large payment up front and don't make the final payment until the greenhouse is complete.

Consider asking these questions to help you choose the best greenhouse contractor:

• Are you licensed, bonded, and insured?
• How long have you been building greenhouses?
• Have you installed greenhouses like this one before?
• How long will it take to build this type of greenhouse?
• Do I need a permit, and will you obtain it?
• Does your estimate include all permit fees, materials, labor, and cleanup?
• Do you offer payment plans?
• Who will be my main point of contact during the installation?
• What ongoing maintenance will this type of greenhouse need?