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Hoklartherm Riga III Greenhouse (10X11)
[MPN: Riga III]

List Price: $7199.00
Our Price: $5999.00
Available Options:
Base Kit:
Drop Down Door:
Heavy Duty Black Seed Trays:
Illumitex LED Grow Light:
Illumitex LED Grow Light (plug):
Misting System:
Moveable Plastic Hooks:
Powered Ventilation System:
Roof Window Restraints:
Roof Window Sash-Locks:
Roof Windows:
Shelf (Bottom):
Shelf (Top):
Stainless Steel Hooks:
Victorian 2-Slat Shelving:
Victorian 5-Slat Shelving:
Wheelbarrow Access Plate:
Quantity Availability: In Stock

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15 year limited warranty The commercial-grade Riga III from Hoklartherm, the leading builder of premier greenhouses in Germany, is a beautiful addition to any garden. Its comfortable 10X11 interior gives you space for anything you decide to grow, and many customers use it as an outdoor sunroom or even for a hot tub enclosure.

Shipping included for the contiguous United StatesThe peak height of almost eight feet allows room for tall plants and growing trees, and there is sufficient interior space for the most avid gardeners. The heavy duty frame is made of reinforced aluminum and the unique "onion" design allows the greenhouse to withstand inclement weather with ease. Nothing short of tornados or hurricanes has ever destroyed a Hoklartherm Riga Greenhouse.

Hoklartherm Riga greenhousesThe Riga III include a large roof window which has an automatic opener to help keep the interior well-ventilated and at a comfortable temperature. The lockable, Dutch door provides easy access and is designed for quick installation.

Hoklartherm Riga III 8mm Triple-Wall Polycarbonate PanelsThe commercial-grade 8mm twin-wall polycarbonate panels on the sides and 10mm twin-wall polycarbonate panels on the front and back provide tremendous insulative value and safety. They are extremely durable and are virtually unbreakable and provide much more efficiency than typical greenhouse panels. Gutters are not needed as the Riga's unique design naturally diverts water away from the foundation.

Despite its large size, the greenhouse can be assembled in as little as a weekend depending on how much help you have. The process can be sped up if the site of assembly is prepared ahead of time by leveling it and installing whatever type of flooring and foundation is preferred.

The Riga III is the type of premium greenhouse which adds to the value of your home. It can serve multiple purposes and its superior build quality ensures that it will stay looking new long after it is assembled. With its durability, attractive design, and spacious interior, the Hoklartherm Riga III Greenhouse is sure to become a showpiece for your family for many years to come.

Hoklartherm Riga III Greenhouse (10X11) from ExacoHoklartherm Riga III Greenhouse (10X11) from Exaco


  • Model: Riga III
  • UPC code: 017783303105
  • Nominal size: 10' width x 11' length
  • Exterior dimensions: 9' 8" width x 10' 6" length x 7' 9" peak height
  • Color: anodized aluminum with smooth finish
  • Floor space: 102 sq. ft.
  • 1 roof window: large 40" width x 24" length vent with temperature-adjustable, electricity-free automatic opener
  • 1 rear roof window is 30" width x 42" height with an adjustment arm
  • Commercial-grade 8mm twin-wall polycarbonate panels on sides and 10mm twin-wall polycarbonate panels in front and back are UV-protected, have a R-value of 1.61 and 1.89, and are virtually unbreakable
  • Heavy duty aluminum frame is greatly sloped with a high peak to allow rain and snow to easily run off and can easily support the weight of an adult
  • Frame profiles are thicker than comparably priced structures for added strength
  • Constructed so that the frame profiles are attached to each other in a manner that ensures that they will stay intact even in high winds
  • High ratio of paneling to frame width allows for maximum light trasmittance and less "moving" shade
  • Heavy duty rubber seals are used on all windows, doors, and the top and bottom of the large side glazing panels for complete weather sealing
  • Barn style door for easy access includes keyed handle and is 30" width x 72" height
  • Tall peak height allows for plenty of working room inside the greenhouse without having to stoop and more room for shelving
  • Gutter and downpipes are not needed because of the unique frame design
  • Beautiful design to fit any garden
  • Includes 4 L-shaped anchor bars which attach to the inside of the frame base profiles to attach the greenhouse to a concrete or wood frame
  • Riga greenhouses have withstood all inclement weather when properly installed and anchored short of tornados and hurricanes
  • Note: Some images may not be to scale or may show the greenhouse with the optional accessories or items such as flowers or tables or chairs which are not included
  • Note: Please be sure to check your local building code for any required permits
  • All Hoklartherm greenhouses are special ordered by Exaco and individually inspected and packed with a 1 to 4 week lead time depending on inventory levels and so returns are expensive; please let us know if you have any questions at all
  • Designed, engineered, and manufactured by Hoklartherm, the top maker of premium greenhouses and outdoor pavilions in Germany
  • Imported by Exaco Trading Co. and shipped from their Austin, TX warehouse
  • Includes comprehensive assembly manual along with a DVD showing each stage of assembly
  • Assembly usually takes just one weekend with two people (three is preferable) with ordinary household tools as there are no eaves and relatively few connections
  • Maintenance-free design means the Riga only needs occasional washing with a garden hose and recommended annual tightening of all nuts and bolts
  • Friendly toll-free technical support available from Exaco for installation help
  • Greenhouse ships in four carefully packed and inspected boxes via ground freight
  • Box 1: 134.5" x 4.3" x 6.7" at 70 lbs., Box 2: 55" x 6.5" x 6.5" at 30 lbs., Box 3: 108" x 5.8" x 2.5" at 40 lbs., Box 4: 119" x 42" x 4" at 126 lbs.
  • Shipping weight: 266 lbs.
  • Exaco and Hoklartherm and Greenhouse Nation stand by their greenhouses and work to make you completely satisfied
  • 15 year limited warranty on frame and 10 year limited warranty on polycarbonate, prorated after 5 years

Optional Accessories

Hoklartherm Riga Greenhouse BaseBase Kit - The base kit used when the Riga greenhouse is assembled directly onto the earth without the use of any concrete or pressure-treated wood foundation. It is made of reinforced aluminum for added durability and ensures that the frame is perfectly square. The lip of the base is actually meant to be placed in the ground, and the base kit is not needed when the greenhouse is already being anchored to a wood or concrete base. The shipping box is 240 inches long by 10 inches wide and deep and weighs 95 pounds.

Hoklartherm greenhouse 20 inch drop down doorDrop Down Door - An extra panel can be placed about the door of the Riga so that it drops down by 20 inches. This allows for the greenhouse to be built upon a stem wall (knee wall) foundation. A stem wall provides a solid base to build upon, raises the peak height by 20 inches, and is universally thought to add to the already beautiful aesthetics of the greenhouse.

Hoklartherm greenhouse 20 inch drop down door

Riga Heavy Duty Seed TraysHeavy Duty Seed Trays - These polypropylene black seeds trays are made in Germany and are perfect for starting seeds in your greenhouse. They are each 24 inches long x 16 inches wide x 3.5 inches deep.

Riga Heavy Duty Seed Trays

Illumitex LED Grow LightIllumitex LED Grow Light - The Illumitex Eclipse GEN2 N Bar LED Grow Light Fixture F3 Spectrum comes either with a 9-foot long power cord or without one so that multiple fixtures can be daisy chained together. Each fixture is 4' long with 12 LEDS and is designed to be installed between 12 inches and 36 inches above the plant canopy. It features 0-10 volt dimming, is damp-rated and dust-resistant, and has a 5 year warranty. The fixture with the plug can be daisy chained and the fixture without a plug includes a 2-foot long cord for daisy chaining. The fixtures have an anodized aluminum frame and are made in Austin, TX.

Illumitex LED Grow Light

Illumitex LED Grow Light

Riga Misting SystemMisting System - The misting system that comes standard with Royal Victorian greenhouses is available for Riga greenhouses. It offers a convenient way to keep your plants hydrated while lowering the inside temperature of your greenhouse on hot days. The standard system is 14' long and will work for a 20' section of greenhouse, though it can be cut down for use in smaller greenhouses. Made in Belgium, the kit includes 5 misters and ships in 2 pieces with a connector.

Riga Moveable Plastic HooksMoveable Plastic Hooks - The moveable plastic hooks come in sets of ten. These snap into the aluminum frame profile and are used for helping orient growing plants such as tomatoes or string beans.

Riga Moveable Plastic Hooks

Riga Moveable Plastic Hooks

Exaco Powered Ventilation System Exhaust FanPowered Ventilation System - A powered ventilation system is available from Exaco to give your greenhouse maximum ventilation on warm days. This system uses a 12 inch exhaust fan, a 16 inch motorized intake shutter, and a single speed thermostat [model VC115-C], all from J&D Manufacturing. The exhaust fan and motorized intake shutter are installed in opposite ends of the greenhouse to provide air flow from one end to the other.

All of the equipment runs on a 110/115V connection. The powered ventilation system can be purchased with just the exhaust fan and thermostat, where one or more of the roof windows can be used for fresh air intake. If the complete system with all components including the motorized intake shutter is purchased, a plug splitter will need to be purchased separately so that both the exhaust fan and shutter can be used with the same thermostat.

The exhaust fan requires a 12.25 inch x 12.25 inch opening and is usually positioned high on the back wall. It comes pre-wired with a 9 feet long plug-in power cord. The intake shutter requires a 16.25 inch x 16.25 inch opening and is usually positioned in the lowest panel in the front wall. It also comes pre-wired and with a 9 feet plug-in power cord. Friendly installation help is available from Exaco for any questions you may have.

Exaco Powered Ventilation System Exhaust Fan

Exaco Powered Ventilation System Exhaust Fan

Exaco Powered Ventilation System Intake Shutter

Exaco Powered Ventilation System Intake Shutter

Exaco Powered Ventilation System Thermostat

Hoklartherm Riga extra roof window with automatic openerRoof Windows - Though this Riga greenhouse already includes a sufficient number of windows, extra roof windows are available to provide even more ventilation. Each window is 40 inches x 24 inches and includes an automatic opener. This opener does not require electricity as it has a special paraffin oil cylinder which expands and contracts based on the temperature. The temperature range on the automatic opener is adjustable.

Hoklartherm Riga extra roof window with automatic opener

Hoklartherm Riga Roof Window RestraintRoof Window Restraints - The roof window restraint system for each window includes two 15 inch stainless steel cables with nuts and bolts. They are recommended for customers who live in high wind areas to help prevent sudden gusts of wind from damaging your roof windows.

Hoklartherm Riga Roof Window Restraint

Hoklartherm Riga Roof Window Restraint

Hoklartherm Riga Roof Sash-LocksRoof Window Sash-Locks - This Riga greenhouse already includes enough sash-locks to keep the included roof windows and top halves of the Dutch doors completely shut during inclement weather. Extra sash-locks are available if extra roof windows are purchased or if customers want some extra just as backups.

Hoklartherm Riga top and bottom shelvesTop and Bottom Shelves - Top and bottom shelves for each side of your Riga greenhouse are available separately from the Complete Accessory Kit. This allows for more floor space and the shelves are strong enough to support the weight of an adult. The top shelf is 10 feet 4 inches long and 10 inches deep and uses polycarbonate inserts to allow for more light. The bottom shelf is 10 feet 4 inches long and 25 inches deep and uses polycarbonate inserts or the optional heavy duty seed trays can be used.

Hoklartherm Riga top and bottom shelves

Hoklartherm Riga top and bottom shelves

Riga Adjustable Stainless Steel HooksStainless Steel Hooks - Ten of these adjustable hooks are available in one set. These are perfect for holding heavier items such as lights or flower baskets and other hanging plants.

Riga Adjustable Stainless Steel Hooks

Janssens Victorian Slat ShelvingVictorian Slat Shelving - The most affordable shelving for Victorian greenhouses is also available for Riga greenhouses. They come in 2-slat or 5-flat sizes and in green or black. The 2-slat shelving is 9" wide x 59" long and the 5-slat shelving is 21" wide x 59" long.

Janssens Wheelbarrow Access PlateWheelbarrow Access Plate - A heavy-duty aluminum access plate is available to serve as a ramp for wheelbarrows over the threshold of your greenhouse. The plate is 21" long on each side x 19.5" wide x 1.75" high in the middle where it is hinged.

Janssens Wheelbarrow Access Plate

Hoklartherm Product Details

Hoklartherm Time Lapse Assembly of Riga XL Greenhouse Side Walls

Hoklartherm Riga Greenhouse Corner Profile

Hoklartherm Riga Greenhouse Foundation Base Profile

Hoklartherm Riga Greenhouse Foundation Frame Corners

Hoklartherm Riga Greenhouse Lower Front Door Assembly

Hoklartherm Riga Greenhouse Upper Front Door Assembly

Hoklartherm Riga Greenhouse Rear Wall Window Assembly (1 of 2)

Hoklartherm Riga Greenhouse Rear Wall Window Assembly (2 of 2)

Hoklartherm Riga Greenhouse Roof Window Assembly (1 of 2)

Hoklartherm Riga Greenhouse Roof Window Assembly (2 of 2)

Hoklartherm greenhouse frame profiles

About Hoklartherm GmbH

Hoklartherm GmbH Corporate Overview (German)

Hoklartherm GmbH HeadquartersSince 1982, Hoklartherm GmbH has been designing, engineering, manufacturing, and distributing premium greenhouses and outdoor structures throughout the world. The company began as a maker of arched greenhouses and the unique Riga design has remained popular ever since. The company was founded by an engineering graduate named Werner Hollander who had built the first prototype in his family's garden a few years earlier.

From this first arched design has come a series of incremental changes to make the Rigas among the very strongest greenhouses available anywhere. The frames have been engineered for strength and to shed off snow and the commercial-grade polycarbonate panels add extra strength to the structure. Hoklartherm now makes beautiful and unique pavilions as well which have been widely installed throughout Europe in parks, commercial settings, and luxury private gardens.Hoklartherm GmbH Factory

At Hoklartherm's headquarters in Apen, Germany, a section referred to as "Greenhouse World" opened to the public in 2012 to showcase all of their unique designs in one place. At this site is the Hoklartherm state of the art factory that employs all the latest quality control techniques and aluminum processing equipment to ensure the very highest and most precise build quality. Hoklartherm is now Germany's largest manufacturer of premium residential and commercial greenhouses and its structures have been enjoyed by happy customers all over the world.

About Exaco Trading Co.

Exaco Trading Co.Exaco Trading Co. began in 1987 as importer and distributor of a home paint mixing accessory called the Exomixer. Since then the family owned company has expanded its line considerably to include many different home and garden products, including some of the very best greenhouses from Europe. The company is led by CEO Kimberly Tyson Cook, formerly an award winning business reporter for the Austin American-Statesman, and Andrew Cook, the VP of Sales and Marketing.

Andrew travels to Europe to check on the manufacturers in person several times a year and has become a leading national authority on all things greenhouse related. He has appeared in many gardening articles and television programs nationally. In fact Andrew is available for phone support for customers during the installation of any of the premier greenhouses that Exaco distributes from its large Austin, TX warehouse.

Assembly Tips For Hoklartherm Riga Greenhouses

While the process of assembling a greenhouse might seem daunting, these kits are designed to be assembled by people even with no prior building experience. Depending on your skill level, the size of the structure, and the number of options you order, putting together a kit can take two or three adults one full weekend.

Many customers opt to hire a local handyman or contractor to simplify this process, and the affordable price of the kits makes it easy to do this. They can be readily found online at sites like AngiesList or HomeAdvisor. A version of the assembly manual is available as a PDF near the bottom of this page to give you a better idea of the process.

Site Preparation - Customers often tell us that the trickiest part of the the process is making sure that they have a good foundation upon which to build the structure. This foundation should extend around the perimeter of your greenhouse. It is ideal to have the foundation be as level and square as possible.

Concrete pavers or pressure-treated wood with crushed stone is often used, though actually pouring concrete will give the most permanent installation. The greenhouse is designed to last for decades, and pressure-treated wood typically will fail well before that when used in outdoor applications, particularly in the ground.

Exaco recommends that all the grass and weeds be removed from inside the greenhouse before assembly and that the area be covered with a weed control mat. Installing the greenhouse on a concrete slab may seem like an easier way to get started, but it's actually less than ideal, as the greenhouse floor should be free draining.

Standing water on concrete can freeze easily in winter months, causing a slip hazard. And concrete slabs don't help regulate the temperature inside the greenhouse as well as other floors such as pea gravel, pine straw, riverbed stones, or just regular earth. Customers typically will create some sort of path down the middle of their greenhouse with flag stones, bricks, or even decking.

Manuals: Hoklartherm Riga IIs-V Greenhouse Manual [2,404 k] 
Manuals: Hoklartherm Riga Greenhouse Warranty [115 k] 
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