Planta Greenhouses vs BC Greenhouses: Which Greenhouse Is Better for Your Climate & Garden Goals?

Updated: November 04, 2025 Published: October 22, 2025

Planta Greenhouses is a European‑engineered brand specializing in heavy-duty, climate-resistant greenhouses designed for year-round cultivation. The company utilizes galvanized steel frames and double-wall polycarbonate panels to provide strength, insulation, and UV protection at competitive prices.

Two flagship models illustrate the brand’s ethos:

Planta Greenhouses Sungrow 20: A bell-shaped 10 × 20 ft greenhouse engineered for harsh winters. Its galvanized-steel frame and 6 mm/10 mm double-wall polycarbonate cladding can handle up to 75 psf of snow and winds of up to 65 mph.
Planta Greenhouses Sigma 20: An arch-shaped 10 × 19.5 ft model using the same galvanized steel and 6 mm double‑wall polycarbonate. Rated for 32 psf of snow and 65 mph winds, it provides solid protection at a lower cost and carries a five‑year warranty.

Together, these models demonstrate why Planta Greenhouses positions itself as both premium and affordable: featuring heavy-duty materials, high snow-load ratings, and generous warranties at prices accessible to serious gardeners.

What This Article is About

This guide provides a clear comparison of the Planta Greenhouses Sungrow 20 and Planta Greenhouses Sigma  20 against their closest counterparts from BC Greenhouse Builders. Each section examines design, materials, climate performance, installation complexity, price‑to‑performance, growing space, and support options.

If you’re wondering how Planta Greenhouses compare to BC Greenhouses, this guide breaks it all down, so you can buy with confidence.

Comparing Sungrow 20 vs. Traditional 16 ft 9½ in × 20 ft 10½ in

Comparing Planta Greenhouses Sungrow 20 vs. BC Greenhouses Traditional 16 ft 9½ in × 20 ft 10½ in (Twin‑Wall)

The Traditional Twin-Wall 16′9½″ × 20′10½″ from BC Greenhouses is the closest match to the Planta Sungrow 20. Below, we break down the comparison across design, materials, climate performance, installation, cost-effectiveness, year-round use, growing space, and post-purchase support.

Design & Aesthetics

Planta Greenhouses Sungrow 20: A bell‑shaped arch with straight sidewalls, designed to shed snow and provide ample headroom. Dual doors and ventilation windows at both ends enhance cross‑ventilation.
BC Greenhouses Traditional 17×21: Angular gable-roofed design with straight sidewalls. The peaked roof provides a more conventional “house-like” look. Customizations, such as additional vents and doors, are available.

Build Materials

Planta Greenhouses Sungrow 20: Galvanized steel frame and 6/10 mm double‑wall polycarbonate, offering UV protection and insulation. Modular extension kits enable scalable length.
BC Greenhouses Traditional 17×21: Heavy aluminum frame with 6 mm twin-wall polycarbonate panels (R-value 1.62). Aluminum resists rust, although it is not as rigid under load as galvanized steel.

Learn which greenhouse frame is better - galvanized or aluminium?

Climate Resistance

Planta Greenhouses Sungrow 20: Engineered for heavy snow with a 75 psf rating (≈ six feet of accumulation). Withstands winds up to 65 mph. Double-wall polycarbonate provides superior thermal retention for winter use.
BC Greenhouses Traditional 17×21: Rated for 32 psf snow load and up to 85 mph wind resistance. Suitable for coastal and temperate regions, though not built for the same extreme snow as the Sungrow.

Planta Greenhouses Sungrow 20 greenhouse

DIY Friendliness & Installation

Planta Greenhouses Sungrow 20: Ships as a pre-cut kit with detailed instructions. Designed for intermediate DIYers and can be assembled on a simple foundation with moderate tools and time.
BC Greenhouses Traditional 17×21: Custom-engineered structure with on-site assembly required. A typical 8×12 Traditional takes 2–3 days for two people; a 16×20 will need longer. More complex than a modular kit.

Price‑to‑Performance Value

Planta Greenhouses Sungrow 20: Priced around US $3,600–$3,900. The combination of heavy steel construction, a high snow-load rating, and a 10-year warranty offers strong value.
BC Greenhouses Traditional 17×21: Starts at US $23,000 (depending on glazing options). Reflects premium aluminum fabrication and a lifetime frame warranty, but at a cost many times higher than Sungrow.

Year‑Round Growing Capabilities

Planta Greenhouses Sungrow 20: Double-wall polycarbonate and tight seals retain heat, supporting winter crops and early spring seedlings.
BC Greenhouses Traditional 17×21: Twin-wall polycarbonate provides moderate insulation; supplemental heat will be required in cold regions. More suited for temperate climates unless upgraded glazing is chosen.

Growing Space & Versatility

Planta Greenhouses Sungrow 20: Measures 94.5 in high × 118 in wide with a 20 ft base length. Straight walls maximize usable bench space, and modular extensions allow unlimited length.
BC Greenhouses Traditional 17×21: Slightly wider footprint. The peaked roof allows tall crops in the center, though sidewalls limit shelving space.

Post‑Purchase Support

Planta Greenhouses Sungrow 20: Backed by a 10-year warranty and responsive customer service.
BC Greenhouses Traditional 17×21: Lifetime warranty on aluminum frame and 10-year hail warranty on polycarbonate. Strong long-term coverage, but with a higher upfront cost.

BC Greenhouses Traditional 17×21 aluminum frame twin-wall greenhouse

Key Differences: Planta Greenhouses Sungrow 20 vs. BC Greenhouses Traditional 17×21

Feature	Planta Greenhouses Sungrow 20	BC Greenhouses Traditional 17×21
Frame material	Galvanized steel	Aluminum
Panel thickness	6/10 mm double-wall polycarbonate	6 mm twin-wall polycarbonate (R 1.62)
Snow load capacity	75 psf (≈ 6 ft)	32 psf
Wind resistance	65 mph	85 mph
DIY difficulty	Intermediate kit, extendable	Advanced custom kit
Warranty	10-year	Lifetime frame, 10-year polycarbonate
Approx. price	US$3,600–$3,900	≈ US$23,000
Seasonal Storage Option	Yes – free storage for winter orders	Not available

Table Text: Side-by-side comparison of Planta Greenhouses Sungrow 20 and BC Traditional 17×21.

Why Choose Planta Greenhouses Sungrow 20?

Heavy-duty design for harsh climates: The Sungrow 20’s galvanized‑steel frame and double‑wall polycarbonate withstand heavy snow and strong winds.
Year‑round gardening: Its bell-shaped roof sheds snow efficiently, enabling reliable growing even in snowy or windy conditions.
Top-rated customer support: A 10‑year warranty and responsive customer service give owners confidence.
Maintenance-free operation: The robust materials require minimal upkeep, delivering long-term durability.

Explore the entire Sungrow collection here!

Why Choose BC Greenhouses Traditional 17×21 Greenhouse?

Classic design with energy efficiency: The Traditional greenhouse uses a straight‑eave design and low‑pitch roof that maximises floor space and reduces heating costs.
Heavy‑duty aluminum frame: BC’s aluminum extrusions are 50–60 % heavier than typical big‑box greenhouse kits and are engineered for 85 mph winds and 32 psf snow loads.
Custom glazing options: Buyers can choose twin‑wall or five‑wall polycarbonate, single or double tempered glass, and tinted or high‑performance glazing to suit their climate and budget.
Lifetime frame warranty: BC backs the Traditional greenhouse with a lifetime frame warranty and 10‑year polycarbonate warranty, reflecting premium durability.

Comparing Sigma 20 vs Pacific 12 × 16

Comparing Planta Greenhouses Sigma 20 vs BC Greenhouses Pacific 12 × 16 (Twin‑Wall)

Comparison of Planta Greenhouses Sigma 20 and BC Pacific 12 × 16

BC Greenhouse Builders does not offer a tunnel‑shaped kit; their Pacific series is the closest option. The 12 ft 4 in × 16 ft 6 in twin‑wall Pacific approximates the Sigma’s footprint and shares a curved eave. Below, we analyze the differences and similarities in detail.