GeneralHow to

Easy to Build Polypipe Greenhouse

Every productive urban garden needs a greenhouse. Whether you need a way to isolate an airoponic/aquaponic system, or just want to give your young seedlings a better chance at survival, a greenhouse is, beyond a doubt, your best option. It protects crops from birds, insects and pets, while also allowing you to fully control their habitat by eliminating unwanted rain, harsh sunlight and strong wind.

Rosina illustrates the location of  the star picket inside the polypipe
Rosina illustrates the location of the star picket inside the polypipe

The problem is, a small to mid-size model will run you about $500 and most Do-It-Yourself guides out there make building one seem too complicated for someone with no experience in construction. Yet, a few time-tested designs require about $50, 2-3 hours of your time and zero experience to complete. No one should pay for something that’s so easy to make. Below is a detailed guide to one of the simplest, yet also one of the most reliable, DIY options out there.


You can buy all of the required supplies in a single trip to your local hardware store. Here’s what you’ll need for one greenhouse measuring 3½ by 8 meters:

• 8 Steel Star Pickets (fence posts) – $7-10 – Try to find the taller posts but anything over 120cm will do just fine. They range from 90 to 240cm in height.

• 20 Meters of Industrial Irrigation Pipe – $20-25 – Make sure you buy polypipe, as opposed to aluminum or steel pipe. You can’t go wrong with thick, 1-1 ½ – inch pipeline but anything thinner than the star pickets you buy is no good.

• 1 Garden Netting (10 x 20 Meters or larger) – $5-8 – Actually, 5x10m is the minimum required. However, you’ll find that garden netting is highly affordable, so you might as well get a larger size. Besides, that extra netting will most definitely come in handy sooner or later.

• 1 Pack of Heavy-Duty Zip Ties – $2-4


Remember – measure thrice to cut once. Consider the height you need to achieve and use a tape measure to estimate the full arch length. Next, subtract the size of your star pickets from it measure and add 100cm to the result. This is done because you’ll be attaching polypipe to your pickets but the fence posts themselves need to be about 50cm underground for reliable support during rough weather. Finally, measure and mark the spot where each fence post will need to be located.

Polypipe greenhouse with Steel Pickets.
Polypipe greenhouse
with Steel Pickets.

Building Process

Once all of your 8 star pickets are in place (two meters apart length-wise) and your polypipe is in four equal pieces, it’s time to construct the base. If piping doesn’t snuggly fit the fence posts, fixate a few zip ties in the picket holes where you want piping to be held in place. Finally, bend the piping into half-circles, attaching each piece to two parallel fence posts.

After the base of your greenhouse is in place, measure out how much netting you’ll need. Try to use one single sheet as opposed to a few separately cut pieces, to maximize protection from insects. If you need sun protection during a hot Summer, just add a layer of clear 6-millimeter Consumer Sheeting on top of your garden netting. So there you have it – a fully-functional greenhouse, large enough to fit all of your seedlings and a small aquaponic system.


The Permaculture Research Insitute

PRI Zaytuna Farm functions as a model farm (in development) and permaculture training facility. Geoff and Nadia Lawton, world-renowned permaculture educators and consultants, lead the project. Much of Geoff and Nadia’s time over the last few years has been spent away from the Institute, consulting and helping set up projects in diverse locales around the world. Seeing the worldwide demand for knowledgeable permaculture consultants and teachers increase exponentially, as fuel and fertiliser prices skyrocket and the effects of climate change, soil depletion and water shortages begin to hit hard, priority and focus is now shifting back to the Institute, where growing the training program will increase the output of quality teachers to help fill the growing need for them.


  1. I am disappointed that this article is a repost from America. In Australia steel pickets are $10 each for a 1.6 m post so eight costs $80 far beyond the $50 total cost this article says. Too often I see things like this posted without regard to what people have to pay in other countries. Often in Australia buying a commercial greenhouse can be equal to or cheaper than the offered diy ideas from America. I would like your site to check the cost for Australia and publish that.

    1. How can they check what the prices are around the world, The article is meant as a guide and u can source star pickets very cheaply online.

    2. I don’t know what your on about Terry.
      US$50 = AU$62.50
      Not far off $80 anyway.
      I’m an Aussie living in Australia, & I would like to know where I can buy a commercial greenhouse in Australia for a comparable price.
      I love this diy greenhouse &. I’m going to give it a go!

    3. Terry, tell us where in Australia we can buy a commercial greenhouse for “equal or cheaper”, tell us your secrets.

  2. Love the idea team thank you for taking the time will likely give this a good go.
    Terry get off your horse mate! $30 difference in aussie is a box of beers.

  3. I just went to a Roberts farm clearance sale. Bought 10 star pickets for $45! I check on gumtree for secondhand items for my farm and go to clearance sales. I picked up new professional grade greenhouse plastic from a dealer selling offcuts from a job. OF COURSE YOU CAN BUILD ON THE CHEAP IF YOU ARE INDUSTRIOUS ENOUGH! Remain positive and you can get great deals here in Australia! I appreciate articles like this!

  4. I think Terry is pretty spot on. It’s still pretty expensive and nowhere near the costs made out in this article.
    Have costed this design up here in Australia.

    8 X 1.6M star pickets = $80
    For 3M width with arch, you will need just under a 6M length per star picket pair. So 4 X 6M lengths at $118 per 6M length = $472
    Shade cloth around $100
    Cable ties $20.

    Total cost, not including weed mat = $672.00

    1. The biggest cost seems to be poly pipe, looks unbelievably cheap in USA! God bless them there, but in Oz poly pipe will cost around $10 per metre if you want something will last more than a couple years.

  5. I’m interested to know what diameter of poly pipe is necessary to fit over the star pickets. Currently in lockdown in Melbourne so can’t go into Bunnings to test the different diameters. Would 1 &1/4″ poly pipe work? If not, where can I get larger diameter poly pipe?

    1. 1 1 /4 (32mm)poly pipe should work for you and fit over the top of the star pickets. We just got ours from Mitre 10 $3.15 a metre.

  6. It’s cost effective if you buy /salvage second hand pickets and poly pipe. I picked up some at a farm sale via marketplace.
    If a pre made one is cheaper go for it!
    I just appreciate learning how to do things and if something is too pricey I’ll look for a cheaper way.
    It all personal choice and I wish everyone joy on their Permaculture journey.

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