Two greenhouses. One brutal storm. One house has little to no damage. The other undergoes severe damage. The difference? Engineering.

Understanding the difference between an engineered (stamped) greenhouse and a non-engineered one—and knowing when to use each—does more than protect your crops.

It prevents costly mistakes and ensures your structure meets local building codes for strength. It also keeps you and your team safe.

Engineered Greenhouses vs. Non-Engineered Greenhouses: What’s the Difference?

Every greenhouse structure had some engineering go into its development at some point. The difference lies in how much customized engineering went into their design.

Non-Engineered Greenhouses

Most manufacturers pre-design non-engineered greenhouses to meet general industry standards, such as basic snow and wind loads. However, these structures do not have site-specific engineering incorporated into their design.

That’s not to say you can’t customize non-engineered structures, but the options are often limited. You might be able to add some extra columns or reinforce the trusses, for example, but major structural changes aren’t part of the design.

Unlike engineered structures, non-engineered greenhouses don’t require a stamp from a licensed engineer or site-specific analysis, and manufacturers don’t provide structural calculations for them.

Growers often use non-engineered structures for general agricultural use in areas where permitting is not required. They’re typically budget-friendly, easy to install, and a great choice for low-risk environments.

Engineered Greenhouses

Designs for engineered greenhouses include custom-engineering to meet site-specific structural requirements, factoring in local weather, soil conditions, permitting regulations, and building codes.

A licensed engineer—registered in the relevant locality or state—must approve and stamp the drawings. This adds to both the cost and the lead time of the project due to the additional design, analysis, and approval process.

Generally, engineered greenhouses are necessary in areas with structural permitting requirements.

People or Plants: Why Occupancy Changes Everything

How you plan to use your greenhouse plays a big role in whether you need an engineered structure or a non-engineered structure.

Greenhouses designed for public access—such as those in schools, research facilities, botanic gardens, and retail garden centers—must be custom-engineered and include stamped drawings to meet strict safety standards.

Production greenhouses, on the other hand, typically have fewer people inside, so their safety and permitting requirements may look much different.

What You Don’t Know Will Cost You: Codes, Risk Management, and Expansion

When choosing between an engineered greenhouse and a non-engineered structure, consider regulatory approval, structural integrity, long-term costs, and future expansion plans.

Compliance and Permits

Engineered greenhouses are mandatory for public-access greenhouses and institutional projects.

If you need to insure or finance your greenhouse, the company you work with may also require a stamped structure.

In areas that require permits, non-engineered structures may not meet code, leading to construction delays, costly modifications, or even a full tear down.

That’s why we always recommend talking to your local building department before purchasing a greenhouse or starting construction. Building codes and requirements vary from location to location. A quick conversation upfront can save you time, money, and frustration down the road.

Structural Integrity and Risk Management

Non-engineered structures carry higher risks in extreme conditions because they’re designed to meet basic structural standards. They may also lack the load capacity to support hanging equipment, baskets, trellising, irrigation, or automation upgrades.

Site-specific engineering ensures a greenhouse can withstand extreme environmental stressors like high winds, heavy snow, and seismic activity.

When an engineer stamps your plans, they’ve reviewed, approved, and taken professional responsibility for the structural integrity of your greenhouse. This Professional Engineer (PE) seal confirms that the design meets local building codes, safety standards, and site-specific environmental factors.

Cost Considerations

Engineered structures require structural analysis and load calculations to ensure the greenhouse meets the durability and safety standards for their location.

Engineers charge for their expertise, liability, and time spent reviewing and approving designs, which adds to the project cost.

However, while engineered greenhouses may cost more upfront, they’re an investment—one that offers long-term reliability, regulatory approval, and the flexibility to expand in the future.

Future Expansion

If you plan to scale your operation, an engineered greenhouse makes it easier to expand. Its design can include built-in features and allowances that let you add on without major headaches or extra costs.

With a non-engineered structure, you might have to reinforce or modify it just to handle the expansion. An engineered greenhouse can be designed with the future in mind—so when you’re ready to add more space, automation, or other extras, you won’t have to start from scratch.

Stamped vs. Non-Stamped Greenhouses: At-a-Glance Breakdown

The following chart sums up the key differences between engineered and non-engineered greenhouse structures:

Factor	Non-Engineered Greenhouse/ Non-Stamped Greenhouse	Engineered Greenhouse/ Stamped Greenhouse
Permit Requirements	Qualifies for ag exempt in some areas if used only for production; depends on local codes	Typically required for institutional, educational, retail, or large structures
Structural Load Capacity	General load assumptions, not site-specific	Custom-engineered for site-specific wind, snow, and seismic loads
Weather Resilience	Limited, may not withstand high winds, heavy snow, or seismic events	Designed to withstand environmental conditions as defined by local and national codes
Customization Options	Pre-designed, limited customization options	Fully customizable to crop needs, automation, expansion plans, etc.
Upfront Cost	Lower initial cost	Higher initial cost
Long-term Cost	Higher risk of sustaining structural damage that may require extensive repairs or complete replacement if not suitable for its location	Lower risk of retrofits, insurance issues, or structural failures
Equipment Loads	May not support additions of heavy equipment, baskets, etc.	Designed to support automation, hanging equipment, baskets, etc.
Insurance, Financing Approval	May not qualify for certain insurance or financing options	Often required for insurance or financing approvals
Ideal Use Cases	Agricultural exemptions, small-scale operations, mild climates	Large-scale production, research facilities, institutional greenhouses, educational greenhouses, retail stores, public gardens

Prospiant’s Non-Engineered Greenhouses

Need a budget-friendly greenhouse for a low-risk area with no permit requirements? If you’re using your greenhouse strictly for production, a non-engineered structure may be the best choice.

Two non-engineered greenhouses in our product line include:

• Windjammer: A robust, freestanding, ground-to-ground greenhouse ideal for finishing and multi-tier production. It supports natural or mechanical ventilation. You can outfit it with environmental controls, heating, shading, and benches.
• Poly Arch: A gutter-connected structure designed for natural or fan ventilation. Its unique roof vent maximizes airflow and cooling, making it an energy-efficient option for production or retail.

Prospiant’s Engineered Greenhouses

Need a greenhouse that meets permit requirements, withstands extreme weather, and supports expansion? Choose an engineered, stamped structure.

Engineered structures in our product line include:

• Vail: A versatile A-frame structure for crop production, retail, shipping, and headhouses, with tall gutter heights for hanging baskets and overhead equipment.
• Open-Roof: Provides outdoor access for crop conditioning with 86° pivoting vertical vents for excellent natural ventilation and partial opening during bad weather.
• Venlo: Highly customizable for any crop or growing system. Designed for maximum light transmission and superior ventilation, making it ideal for both produce and ornamental crops.
• Techlite: A-frame design with double-skinned, insulated glazing material especially for universities, research facilities, schools, and botanical gardens.
• The Glass House: Aluminum A-frame house with a glass glazing system, designed for universities, research facilities, schools, and botanical gardens.
• Classroom Cultivator: State-of-the-art A-frame adaptable for any use. Accommodates various ventilation styles, growing systems, shade systems, and heating and cooling systems. Adheres to school safety and building codes. Suitable for elementary school to high school greenhouses.

Discover more about these structures and explore our comprehensive product line of greenhouses and related services on our Products page.

The Building Department Might Not Speak Greenhouse—But We Do

Building codes and permitting can be complicated, so consult with your local building department before purchasing or constructing a greenhouse.

That said, not every permit requirement is set in stone. Some officials may be unfamiliar with greenhouse structures, so if something doesn’t sound right, check with your greenhouse supplier for clarity.

Prospiant’s team of designers, engineers, and project managers can help you navigate permits, respond to review comments, and interpret the International Building Code (IBC), ensuring you explore all options and exemptions when challenges arise.