Greenhouse growers know that yields and technology matter, but long before you install the most advanced climate controls or automation, one factor determines just how successful a greenhouse can be: structural engineering.

The backbone of every productive, weather-resilient greenhouse isn’t visible on day one, but it’s present in every calculation, material choice, and joint. A grower’s peace of mind, especially when facing unpredictable North American winters or high winds (both combined, too!), depends on engineering that blends safety, performance, and longevity from the ground up.​

At Harnois Greenhouses, this engineering mindset is woven into every project, ensuring that each structure is more than just a shelter for crops; it’s a safeguard and an investment in reliable, long-term production. To explore how next-level engineering frees growers from weather worries and maximizes crop outcomes, Horti-Gen Insights sat down with Carl Savard, Chief Structural Engineer, P.Eng., at Harnois Greenhouses.

His perspective offers a behind-the-scenes look at how thoughtful design keeps risk low, production steady, and growers confidently focused on their crops, no matter the climate.

Engineering as a Foundation for Performance

“For us, engineering is always the first step,” explains Carl Savard. “It defines the design that will deliver the best balance of strength and performance for the client.”

Each Harnois project starts with a thorough assessment of the greenhouse’s purpose, location, and expected environmental loads. This approach ensures that durability, compliance, and operational efficiency are considered from the very beginning. Instead of designing from standard templates, the Harnois’ engineering team tailors every structure to match local climates and production requirements.

The outcome is consistency: greenhouses that retain strength through changing weather patterns, maintain operational stability, and provide long-term return on investment.

Designing for Diverse Climates: From Harsh Winters to Southern Winds

Harnois Greenhouses has established its technical reputation in Quebec, where heavy snowfall and ice pose significant structural challenges. Yet, as Carl Savard points out, those same engineering principles create advantages for clients working in the southern United States and Mexico.

“Our greenhouses are custom-designed, which means we can offer the best configuration for a client’s crop and climate,” he says. “In northern regions, we adapt the dimensions to improve snow load resistance. Further south, the design shifts to reinforce wind resistance while allowing maximum light with spacing between arches of up to four meters.”

This adaptability results in a greenhouse that performs efficiently year-round. Whether standing up to blizzards in Canada or high winds in coastal regions, each model remains stable, bright, and optimized for local production goals.

Harnois's reputation for technical mastery and expertise extends as far as the Caribbean, for example, in Bermuda, with structures that can withstand winds of over 150 mph.

Anticipating Weather Extremes Through Calculated Precision

Extreme climate events have become the new norm across North America. Designing for these conditions requires an engineering process that anticipates stress rather than reacting to it. “At Harnois, we design based on precise criteria,” says Savard.

This meticulous approach allows the structure to maintain integrity under unpredictable environmental conditions. The result is an engineered peace of mind for growers: predictable performance, fewer surprises, and minimized risk of structural failure.

Engineering for Light, Ventilation, and Productive Climates

Mechanical strength is only one part of the story. Engineering at Harnois also drives agronomic efficiency by shaping how light and air move through the space.

“Light transmission and climate management are critical for yield,” notes Savard. “That’s why our Luminosa greenhouse line lives up to its name. Instead of crowding the roof with extra bracing, we design thicker or larger structural sections to preserve roof transparency. That keeps light levels high without compromising strength.”

Ventilation and energy efficiency benefit from the same integrated logic. Taller structures improve air exchange and temperature control. Depending on the number of spans, the engineering team carefully sizes the posts to ensure ideal stability while enhancing overall climatic balance.

These design decisions directly impact productivity. Less shading, improved airflow, and enhanced structural stability result in stronger crops and better year-round conditions for growers working with vegetables, berries, ornamentals, or specialty crops.

Carl Savard also notes that this expertise extends beyond conventional agriculture. A notable example is the Key West Butterfly Conservatory, where Harnois adapted its greenhouse engineering principles to meet both environmental and aesthetic requirements, demonstrating structural creativity beyond farming. This reinforced gutter-connected structure has already experienced several Type 5 Hurricanes without any issues.

What Makes Harnois Greenhouses Stand Out

In the competitive North American market, the difference between a good structure and a great one often lies in the details and in how much the engineering team listens to growers.

Rather than reducing arch spacing or increasing bracing to meet higher load requirements, Harnois Greenhouses chooses a different path. “We preserve optimal spacing for light and adapt the steel sections to increase strength where needed,” says Savard. “It’s a more advanced way to enhance resistance while keeping the structure bright and efficient.”

This philosophy is backed by practical flexibility. When a client faces technical or terrain-specific challenges, Harnois offers design adjustments instead of standard compromises. Whether that means creating custom components, reinforcing localized areas, or designing an asymmetrical structure for uneven terrain, every project is guided by what will be most reliable and cost-effective for the grower.

The result is not a standard product, but a collaborative, engineered solution—one that reflects both Harnois’ experience and its family-driven ethos of precision and trust.

Adapting to Changing Codes Across North America

As construction and engineering codes evolve, staying compliant is both essential and complex. For Carl Savard’s team, this adaptability is built into the company’s DNA.

“We constantly monitor changes in Canadian and U.S. codes,” he explains. “Because our designs already cover snow and wind regions, adjustments to increased standards are straightforward. The biggest challenge appears when expanding an older greenhouse that no longer matches current codes. In those cases, we design the new sections so they don’t share structural loads with the old frame.”

This careful division ensures safety and compliance during expansions—protecting the grower’s investment and keeping operations uninterrupted.

Conclusion: A Trusted Engineering Partner for North American Growers

As agriculture evolves toward more controlled and sustainable production, the reliability of greenhouse engineering becomes inseparable from crop success. The next generation of structures must not only adapt to extreme weather patterns but also integrate seamlessly with automation systems, efficient materials, and long-term operational goals.

That balance—between resilience, clarity, and performance—is precisely where Harnois Greenhouses stands apart. For over 50 years, the company has drawn strength from its engineering-led approach and its family values of quality and service. Every calculation, every welded section, and every design standard reflects a commitment to grower confidence.

Engaging with Harnois Greenhouses means eliminating guesswork around wind and snow loads. It means investing in streamlined, light-filled structures designed for strength, safety, and productivity—across any region, for any crop.

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