At Harnois Greenhouses, we design and deliver greenhouse projects tailored to the specific demands of modern agriculture. From initial feasibility studies to full turnkey installation, our engineering team combines decades of horticultural expertise with cutting-edge structural technology to ensure every project meets the highest performance standards. Whether you require a large-scale high polytunnel, a precision Venlo glass greenhouse, or a fully climate-controlled production facility, we provide end-to-end solutions adapted to your crop, climate, and production goals. Every greenhouse project we undertake is backed by rigorous technical planning, certified materials, and dedicated post-installation support, delivering measurable results from day one.
Commercial Greenhouse Projects Across North America
With more than 10,000 completed installations across Canada, the United States, and Mexico, Harnois has built a track record that spans every major crop type and climate zone. Our greenhouse projects range from small-footprint freestanding structures for nurseries and garden centers to multi-hectare gutter-connected complexes for large-scale produce and soft fruit growers. Each project is engineered on-site and manufactured in Quebec, ensuring every structure meets the structural requirements of North American building codes and weather conditions, from coastal British Columbia to the Gulf Coast.
Our portfolio includes projects for some of the most recognized names in commercial horticulture: Red Sun Farms in Mexico, Zordi in the United States, Canadian Tire garden centres across Ontario, and hundreds of independent growers who rely on Harnois structures to produce year-round.
A Turnkey Process Built Around Your Production Goals
Every greenhouse project at Harnois begins long before a single post is set in the ground. Our team of agronomists, structural engineers, and project managers works with you during the pre-project phase to assess your site, define your crop targets, and select the structure type that best fits your operation. This planning-first approach is what sets our projects apart from commodity greenhouse builders.
Once the design is finalized, our in-house manufacturing team produces every component, steel frames, covering systems, ventilation hardware, at our facility in St-Thomas, Quebec. Deliveries are coordinated to match your construction schedule, and our field installation teams manage the full build, from foundation to first crop. According to the American Society for Horticultural Science, proper greenhouse design and climate management can improve crop yield predictability by up to 40% compared to open-field production, a metric our engineering team keeps top of mind throughout every project.
Greenhouse Structures for Every Crop and Climate
No two greenhouse projects are identical. A strawberry grower in Ontario has fundamentally different requirements from a cannabis producer in Quebec or a pepper operation in Sonora. That’s why Harnois offers the broadest range of commercial greenhouse structures in North America, including:
High Polytunnels and Field-Scale Tunnels Our TunnelPro Plus and field-scale polytunnels are engineered for growers who need to extend their season without the capital cost of a permanent structure. These projects are particularly popular for strawberries, bare-root plant production, and cannabis operations.
Gutter-Connected Greenhouses The Luminosa gutter-connected greenhouse is our most deployed structure for large-scale produce and ornamental operations. Its wide-bay design maximizes growing space while the multi-span configuration reduces heating costs per square foot, making it the structure of choice for projects exceeding 10,000 sq. ft.
Venlo Glass Greenhouses For operations where light transmission and long-term durability are non-negotiable, our Venlo glass greenhouse delivers 98% light transmission with a structure built to last 30+ years. These projects are common in research institutions, high-value vegetable production, and floriculture operations.
Freestanding Greenhouses Our Ovaltech freestanding greenhouse remains a top choice for garden centers, nurseries, and smaller commercial operations that need a flexible, expandable structure with a minimal permitting footprint.
Integrated Equipment for a Complete Growing System
A greenhouse is only as productive as the systems inside it. Every Harnois project can be equipped with a full suite of growing technologies and equipment: LED and HPS lighting, thermal and blackout screens, irrigation systems (drip, flood floor, boom), mechanical ventilation, and elevated or flood benches. Sourcing your structure and equipment from a single supplier eliminates integration issues and gives you a single point of accountability from design to harvest.
Start Your Greenhouse Project
Whether you’re planning your first commercial greenhouse or expanding an existing operation, our team is ready to help you move from concept to production. Browse the projects below to see examples of what Harnois delivers across North America, then request a quote to start the conversation.