Riga 4 Black 9x14 Greenhouse

Riga IV Black 9x14 Greenhouse — German-Engineered, Four-Season Growing

The Riga IV Black (also called the Riga 4 Black) is a 135 sq ft, four-season greenhouse engineered and manufactured in Germany by Exaco — a company with 28 years of greenhouse manufacturing experience. It shares the same 9'8" wide "onion" arch profile as the Riga III but extends to 14 feet in length, adding 33 sq ft of growing area and a second automatic roof opener for superior ventilation across the full interior.

The Black Series upgrade adds a black powder-coated aluminum frame, 6mm crystal-clear single-layer polycarbonate front, and Victorian cast metal roof cresting — delivering refined European aesthetics without compromising structural performance. The Riga IV Black is rated to 100 mph winds, carries a 15-year frame warranty, and ships in 1–2 weeks.

Ships in 1–2 weeks.

What's Included — Basic Package

• 6mm crystal-clear single-layer polycarbonate — front gable and door
• 8mm UV-coated translucent twin-wall polycarbonate panels — sides and roof
• 10mm translucent twin-wall polycarbonate panels — rear gable (added strength)
• 2 roof vents (22" × 40" each) with automatic openers
• 1 rear wall window (3'5" × 2'1")
• Split dutch hinged door with keyed lock
• First-class insulation — R/K-value up to 1.89
• 15-year warranty on aluminum frame
• 10-year pro-rated warranty on polycarbonate panels

Build Your Package — Available Add-Ons

Configure your Riga IV Black using the options above. Each add-on ships in the same delivery:

Riga IV Black vs. Riga III — Key Differences

The Riga IV Black and Riga III share the same 9'8" width and 7'7" peak height. The Riga IV adds 3'6" of length, 33 sq ft of growing area, and a second automatic roof opener for improved ventilation across the longer interior.

Riga Series Comparison

Frequently Asked Questions

What is the Riga IV Black greenhouse?
The Riga IV Black is a 135 sq ft, four-season polycarbonate greenhouse manufactured in Germany by Exaco. It features a black powder-coated aluminum frame, a crystal-clear 6mm polycarbonate front, and 8mm/10mm twin-wall polycarbonate side and rear panels. It is rated to 100 mph winds and includes two automatic roof vents for year-round temperature regulation.

Why does the Riga IV have two roof windows instead of one?
The Riga IV's 14-foot length requires two roof windows to provide adequate ventilation across the full interior. A single roof window at one end would leave the far end of the greenhouse with insufficient airflow on hot days. The two automatic openers work independently, allowing the greenhouse to self-regulate temperature along its full length.

What is the difference between the Riga IV and the Riga IVs?
The Riga IVs is the shorter "S" variant of the Riga IV series. Both models share the same 9'8" width and 7'7" height. Contact us for the specific length and pricing of the Riga IVs if you are comparing the two models.

Do I need the base kit (foundation frame)?
The base kit is strongly recommended for soil or lawn installations. The Riga IV base kit is a 6" H × 116" W × 168" D aluminum frame buried in a trench and backfilled with soil to anchor the greenhouse and raise the interior height by 6". Without a proper foundation, the greenhouse may shift over time. If installing on an existing concrete pad, the anchor option (+$99.99) may be more appropriate.

Can the Riga IV Black handle heavy snow loads?
Yes — the "onion" arch profile sheds snow automatically. The Riga IV has been tested against winds up to 100 mph and has never been blown away when properly anchored with the base kit or anchor option.

How long does assembly take?
Assembly takes approximately one full day for two people. Written instructions are included. The Riga assembly facilitation kit (metric tape, 10mm wrenches, ratchet straps, Boss 399 silicone caulk, window restraint cables) is available separately and contains all the specialized tools needed for the build.

Is the Riga IV Black expandable?
No — the Riga IV Black is a fixed-length model. If you anticipate needing more space in the future, consider the Riga XL series, which is designed to be expandable by adding additional sections.

What polycarbonate thickness does the Riga IV Black use?
The Riga IV Black uses three polycarbonate thicknesses: 6mm crystal-clear single-layer on the front and door for maximum light and visibility; 8mm UV-coated twin-wall on the sides and roof for insulation and durability; and 10mm twin-wall on the rear gable for added structural strength.

Is the Riga IV Black suitable for year-round growing in cold climates?
Yes. The twin-wall polycarbonate panels provide an insulation R/K-value of up to 1.89, and the "onion" arch profile sheds snow without accumulation. The greenhouse is engineered for four-season use in cold climates, including regions with heavy snowfall and sub-zero temperatures.