Prefab Greenhouses for Sale | Prebuilt Greenhouses

Prebuilt Greenhouses

6 x 8 “Elite” Greenhouse

Are you new to gardening? Someone with a few growing seasons under your belt?  New or experienced, a backyard greenhouse allows you to take the your ‘green thumb’ to the next level.  And, with a Horizon Structures pre-built greenhouse it’s easy and relatively inexpensive to do!  

A greenhouse in the backyard allows you to…

  • Extend the growing season (maybe even year-round depending on your location).
  • Start seeds early and inside.
  • Expand your options for a wider variety of vegetables and flowers.
  • Stop worrying about the weather.
  • Protect plants from bugs, birds or pesky nibbling rabbits, squirrels and other wildlife.
  • Maintain correct and consistent moisture and temperature levels for bigger, healthier, and faster growing plants.
  • Use built-in potting benches to work with ease and comfort. No aching back or kneeling in the dirt. (*potting bench optional)
  • Store containers, tools, and gardening supplies in one convenient place.

A PREBUILT Horizon Structures greenhouse allows you to get started immediately!  NOT a kit ~ NO ASSEMBLY required.




Choosing the right backyard prefab greenhouse is not a decision to take lightly.  There are plenty of options available and many models to choose from.  Large big box stores sell greenhouses.  Greenhouse kits are also available online.  However, neither of these is necessarily the best choice in the long run. Here’s why…

A Horizon Structures prebuilt greenhouse is the right choice for a number of reasons.  First and foremost, the strength, weight, quality and durability of our raw materials ensure that a Horizon greenhouse stands up to harsh wind and weather throughout the seasons year after year after year.

Another advantage is that Horizon prefab greenhouses are NOT kits.  We deliver them fully assembled and ready for immediate use.  You won’t waste time fumbling around putting our greenhouse together.  As soon as we get it off the truck, you can dig right in and start getting your hands dirty!  Let the planting begin!

  • Attractive, classic design in a wide range of sizes:  6’ x 6’ to 8’ x 16’
  • PREBUILT greenhouses are delivered fully-assembled and ready for immediate use – THIS IS NOT A KIT!
  • No special site prep required
  • We ship throughout the Continental United States
  • Available year round

Base / Frame / Foundation

As a general rule, greenhouses are relatively light compared to their size and may blow over or suffer wind damage if not properly anchored.  We’re proud to say, there’s nothing lightweight or flimsy about a Horizon Structures greenhouse.  They’re heavy and sturdy incorporating a robust 4x4 pressure-treated wood foundation ‘frame’ that keeps the structure upright, square and solidly in place.

This extra strong foundation – or base frame – securely holds the structure together AND enables you to easily anchor it firmly to the ground for increased peace of mind.

The pressure treated wood also reduces (or eliminates) damage from dampness in the ground and insect infestations.


Siding and Framing

  • Stud walls and roof rafters are sturdy Southern Yellow Pine (‘SYP’) 2 x4s / 24” o.c. construction.
    • Increase the capacity (… and beauty!) inside your greenhouse by adding hooks for hanging plants.  The solid framing won’t let you – or your plants – down!
  • Steeper pitch roof sheds snow efficiently
  • Roof and wall panels are heavy-duty 8mm twin wall polycarbonate.  This UV-resistant greenhouse material is 12 times lighter than glass.

Clear polycarbonate panels make up the roof and sides of the backyard greenhouse.  They are neatly sandwiched between the interior wood framing and Azek exterior trim.

Azek is a multi-purpose construction material made of cellular PVC.  It is durable and long-lasting.  It does NOT require paint for protection but holds paint well should you decide you want something other than the standard white.

Azek never needs maintenance. And, unlike wood, it resists mold, mildew, stains, and scratches.  It’s splinter-free and comes with a 30-year manufacturer’s warranty.

The 8mm twin wall polycarbonate panels offer improved insulation for both hot and cold weather and are superior to fragile glass or plastic sometimes used in greenhouses.  In the unlikely event these durable panels need replacement, simply unscrew the (exterior Azek) trim and put in a new panel.

Other benefits of polycarbonate…

  • Will not film over after long exposure to sunlight.
  • Tough, practically shatterproof.
  • Maintains light transmission over years of use.
  • Hollow, twin-wall construction gives superior insulating capabilities for better heat retention
  • Virtually no UV penetration.
  • Highly flame resistant, with a flashpoint of 1,166˚F.
  • 10-year manufacturer’s warranty.


  • 32’ x 80’ storm door.  Includes solid, clear windowpane with screen option.
  • 18” x 23” jalousie window for ventilation.  Mounted on the back wall.  Just reach up and open/close with a simple crank handle.


Horizon Structures Greenhouses ~ A Gardener’s Delight

Our greenhouses are beautifully crafted from the ground up by Amish carpenters and include a pressure treated, 4 x 4 Southern Yellow Pine (SYP) base that will stand the test of time. All that’s required is a level, well-drained area. A specially prepared site is not necessary unless you prefer that route.

The ‘floor’ of your greenhouse can be finished in a myriad of ways before or after delivery...

  • Concrete slab
  • Pavers, bricks
  • Gravel
  • Mulch
  • Your choice!

Upgrades make it even better!

Have us add a sturdy, built-in potting bench. Mounted a convenient 36” high.  Benches are attached to the wall creating a stable, wobble-free workspace.

Surface is a heavy-duty polypropylene panels.  Durable, smooth and non-porous.  Easy to clean - No splinters or rough edges - UV protective - high impact - abrasion resistant.  Securely screwed onto wooden bench frame so there's no slipping or sliding around.  Square holes allow water, potting soil and debris to drain right through.

Holds everything from your delicate seedlings to bags of potting soil.  Will not dent or warp.

  • Choose 17” or 24” deep
  • Add thermostatically controlled fan to provide automatic ventilation during hot weather. 1-year warranty included. 110v.
  • Includes louvered window
  • Fan has 3 speeds
  • Thermostat range:  40˚F to 110˚F
  • Tolerates moist conditions:  water spray and high humidity
  • Resists corrosion



What A Difference A Greenhouse Makes

Hassle-free, quick, and efficient delivery provides an ‘instant’ gardening solution so you can get busy planting and growing right away. 

Hobby gardeners and Master Gardeners alike will be delighted by the benefits and possibilities of owning a Horizon Structures greenhouse and the ease with which this prefabricated structure transplants itself from our factory floor to your garden. 

Need help? Have questions? Count on our Customer Service team to guide you through the simple purchasing process and help you choose the right greenhouse for your needs. Don’t forget to ask us about financing!  Call Today:  888-447-4337

We Make the Process Easy