How to Build a Greenhouse

Here in the Upper Midwest, the gardening season is short, typically May through September. By building a greenhouse, we can harness the sun’s rays to let plants thrive as early as March and extend harvest into late fall. A greenhouse is also a great place to store less hardy plants during harsh winters.
Even if you live in a more temperate region, a greenhouse will create a perfect climate for plants, protecting them from temperature swings, storms and pests. We built our greenhouse from cedar, which weathers beautifully, and polycarbonate sheets, which diffuse the sunlight and give even exposure to all the plants. Get more project details at: www.familyhandyman.com/projec...
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[@TheMontyOriginal]

This is my dream greenhouse!

[@tedtolentino4955]

A beautifully built greenhouse. I'm a bit curious why the baseplates of the walls were set on the gravel flooring of the foundation as opposed to the perimeter pressure treated wood. Thanks for sharing your video.

[@jayong2370]

You make it look so easy! You’ll have the skills to build a house after that for sure 🙂

[@pamelaharrison3196]

Beautiful greenhouse

[@johnminock1925]

Why not frame it on the timbers that you set in place? Construction is extremely clean! Well done.

[@mikeash7428]

Good job. Thanks for showing

[@neuralfraud]

Greenhouse with 16" studs. Overkill. Nice job!

[@techheck3358]

No ridge beam? Or rafter ties? Vapour barrier? Treatment or paint of that raw wood?

[@nopnop6274]

Excellent Video! I Loved it ❤❤ Thank you for sharing! This is exactly what I was looking for, very well presented, and wonderfully done.

[@edwardnewbins]

Great video!

[@SnakeAndTurtleQigong]

Thanks so much

[@hawkeye1009]

Beautiful job! I'm quite impressed by how you thought of every detail and finished it all off so nicely, including the groove for the drip edge above the wood panels. Just Lovely.

[@danmallery9142]

Just out of curiosity, what was the materials cost for the project? Thanks.

[@MindscapeX]

Great build, would have been better if you included links somewhere for the fans and lights you used.

[@rattlecat5968]

Beautifully designed, well executed, clearly explained. This will be my 2023 garden project! THANK YOU!!!

[@aarspainting81]

how did it go?

[@originalfallinggirl]

This has helped me understand framing so well 🙏

[@mike32487]

We built a real nice aluminum one last year. Lasted 2 months before the wind took it completely down. We need one of yours! Looks tornado proof!!

[@zerrak_zeor2503]

I build a Aluminum one like that myself I told my mother it would fall over again and again without more supported before she even had me build it. The structure clearly needed to be reinforced around it needed more Anchorage to the ground. I tricked her into getting a small amount of more materials so I could create Anchorage and designed connection points so I could build a supporting system. She never ok the adding of a support structure. Luckly once the roof was wiped out by the first super windy day as it fall apart like house of cards. Aluminum parts stay in place but were extremely warped. The panels went flying through the air like sharp knives it was so luckly they were all stabbed to the trees or the ground when all was done because as fast as they were fly about they could have easily kill someone. I watched from behind a impact resistant window as it just came apart. My mother sadly never developed any structural common sense and just keeps repeatly making similar mistakes. She once tile over a porch that was basically nothing but rotten wood after she was told it was rotten wood was completely unsafe and needed rebuilt. She reply by jumping up and down on the porch and said why am I not fall through the floor. It was a pure mass thing because the original supports were 6 by 4's and every time she jumped they fall apart more which was leading to a catastrophic failure. When her tile started to crack apart as the supportive structure give way I rebuild it from the bottom crawling around under the floor with limited space. I use carjacks on cinder blocks to level and support the floor as I rebuild the floor. The floor have a layer of wood boards and a layer of concrete boards as built new concrete supports to support new wood framing that was completely independent structurally from what was previously supporting the floor. Now once the bad wood fall off nothing was going to happen but the need to replace a few face boards which were looks only and would be a cheap easy fix. One she never let me do. How the porch was even supporting any weight was a shock as you could pull pencils through like 75% the wood with the strength of one finger and it wasn't even hard at that. I told her when all was done I could have built her a whole new porch faster and wouldn't have costed much more. It all makes for some funny memories in the end because no one got hurt. I think my parents being so bad at builting is what made me so obsessed with it really. Do you live in Florida near tampa? because by brother is a contractor and depending on your budget maybe we could help you out.

[@joanies6778]

This was educational and a lovely greenhouse. I'm sure the homeowner was over the moon with this nice clean build. For myself, if I'm going to build something this elaborate and expensive, I want to use it for more than seedlings in the spring. I would want to be able to grow things at ground level, in the winter, even if just in pots. So, I would opt for wire shelving that can fold out of the way or be moved when not being used for seedlings. I don't get why anyone would need grow lights for 24/7 light... nothing in nature has that. Otherwise, I loved everything else about the project.

[@snowhero9]

You are right about the uses and folding shelves. Most plants will grow faster with more light. Many are triggered by the changing seasons and lighting gives the gardener more control of the trigger. Lights are great for long periods of overcast weather and create heat when they are most often used (fall, winter) helps keep the temps up.

[@contemplating1015]

This top quality American timber construction technique👌 big respect from🇬🇧

[@AnnWelch-jy7ds]

In GB that would be considered a house extension. The cost would be astronomical and definitely overkill for a greenhouse. I personally wouldn't use polycarbonate for windows, it would be like gardening in a tent, no view at all. An easier way to deal with glass is not to cut the glass to suit the construction but to make the construction fit the standard glass sizes !

[@riverrat8693]

Isn't it better to use rubber washers for the screws into the poly, and to use poly U connections, and poly ends and caps instead of wood?

[@tripplevirgo]

Nice job , looks great

[@ogj5]

OMFG PLEASE build me one! LOL This thing is awesome. Your sill design is genius. WOW. Well done. I am the worst carpenter. This is next level.

[@FrederickDunn]

Excellent presentation! I'm a tad worried about the polycarbonate since it's only good for about 10 years. What are you thinking the life of your structure is, and why not just go for glass? I got some great ideas from this, thank you.

[@riverrat8693]

You have to listen 👂. He said glass is to expensive which it is, it's also more prone to breaking, has a worse R value, is much more difficult to install, and it doesn't diffuse the light as well polycarbonate sheets. IMO twinwall and triple wall polycarbonate is far more superior. Light diffusion and heat retention is a big deal. Glass is overrated.

[@FrederickDunn]

@@riverrat8693 Thanks for sharing your opinion on that.

[@riverrat8693]

@@FrederickDunn lol sorry for being rude. I guess if money's not a issue some kind of double paned glass that diffuses the light is the best but it probably costs a small fortune but will last forever unless it gets w broken. Most commercial greenhouses just use polycarbonate ends and poly film tops.

[@riverrat8693]

@@FrederickDunn for cold climates triple polycarbonate is amazing. That's what I'm going to use to keep down on propane costs.

[@joanies6778]

​@@FrederickDunn Yeah... Glass would not work in my area. We have hailstorms to be concerned about. It's much cheaper and easier to replace polycarbonate.

[@andrewyang1446]

It’s a beautiful little greenhouse! How much would something like this cost? I almost want to live in it.

[@quincybirwood2629]

Awesome! That video was chocked full of great ideas and clever craftsman tricks. Thanks for posting.

[@wisconsinbush2940]

What is the purpose of building the walls on the gravel versus the Timbers? Especially in the winter months won’t the frost go through the rocks.

[@mariafhp]

Excellent and detailed presentation . Thank you 💯👍👏❤️

[@specialnici09]

Do you have the link for the Lights and ventilator? Great job ✌

[@Steve-ps6qw]

That is pretty damn great! Thanks!

[@riverrat8693]

Can't you use frame it at 4ft studs and use poly U connections?

[@tinaabc3219]

Thank you for coming up with a design that's made to last and to stand up to the extremely high winds where I happen to live.

[@ironrose888]

This is my dream greenhouse 😊

[@craiglawrey7518]

Well done!

[@JonSteitzer]

I've seen a lot of construction youtube. you guys are the real deal

[@otherSid098]

It's amazing how this greenhouse is the cover pic for the latest Family Handy Man magazine!

[@FloridaGirl-]

Super rugged! That will beable to withstand just about any bad storm or high winds! Nicely made! 👍

[@JinendraBandara]

Beautifully done. Clean job. How much did you spend on this thanks

[@mdube391]

Really nice end product. This is a beautiful greenhouse for starting plants. Thanks for the great video

[@paulsuba6212]

I like your work!

[@mikesbikes1575]

Great job... if you have an unlimited budget. 😉

[@mommytweety7157]

How are you powering the fans and lights?

[@ika5663]

Great video.

[@bitorajac1]

iagree, why not just put it on the 4x4 and have a much bigger greenhouse? does this allow the gravel to dry up from the out side?

[@warrenb9343]

Outstanding video and product! The Johnsons are very fortunate to have this. With the cost of wood now, especially cedar, I'd need another mortgage for one of these!

[@user-xf2sw9ou3d]

У нас в Сибири , 1 кубометр кедра стоит 200 € . Не знаю дорого это или нет )

[@janus878]

Einfach nur großartige Arbeit , fängt schon am Boden an: kein Beton😍Nur die Inneneinrichtung habe ich nicht verstanden: durchgehende Arbeitsplatten anstatt Latten, die das Licht durchlassen würden und das auf beiden Seiten, wo sind die Erdbeete in so einem tollen Gewächshaus😢

[@wordimobi5765]

An excellent example of solid, functional, simple construction. What would be an alternative way to fix the building to the ground?

[@dakotalyons1414]

lag bolts and washers

[@davidcarmichael8006]

where can I find that plastic you used on the outside?

[@user-oh7ke2bj5b]

How far apart do you put studs

[@christiekrueger1984]

That's so pretty. I am a big gardener and it would be a dream to have one.

[@ryanwood762]

What size is this and what’s the estimated cost?

[@artkyger3425]

I built greenhouses for a commercial wholesale greenhouse operation. The legs of the flower beds should be concrete block. The wood on the flower beds should be cedar or better yet redwood as the 1x4 you used will quickly rot with the watering. Watering tubes between pots and Stuppy Green House Supply can provide the watering tubes for the flower pots not to mention the watering caps to go into the flower pots. You need spaces between the boards on the flow benches. You may need a convection tube in the top of the greenhouse.

[@timmoore9736]

Well done in explanation, but seems to mirror the proverbial brick outhouse - overkill! Then, again perhaps the upper midwest is a tad bit tougher weather-wise.

[@IronJohn755]

This structure is highly overbuilt and impractical - the world's most attractive and expensive potting shed.

[@vikramjangam]

Do you recommend anyone in Dallas ?

[@frankmeng7138]

What’s your budget for this nice greenhouse? Thx!

[@salahsaid2163]

What it is used for please ?

[@caidencondon3171]

Where did the grow lights and fans come from?

[@HenrySeagull]

Would this be considered a Temporary Structure AKA No permit required?

[@LouReef69]

thank you. very detailed.. could you. please have a list of those growlights fan and auto ventilation ?? thank you again

[@LouReef69]

anything?

[@tundradave138]

I purchased fans from Amazon. AC Infinity for the exhaust and simple deluxe for the circulating. Can't speak for the quality or durability, since I just got them.

[@LouReef69]

thank you very much .. really appreciated, please keep posting updates.

[@dimmer4955]

9:05 After shelling out $10,000 worth of work and materials, this guy said that putting tempered glass there would be an expensive option)))

[@Guns.Flowers]

Доста симпатично

[@shannonnewman3091]

Nice !

[@peaceenjoyer]

thank you

[@kr5289]

why didn't you set the walls on the 4x4 base.

[@bonnenaturel6688]

a few weeks to build???

[@raven_glass]

So much work put into those anchors and the stone foundation. Would have been easier just to pour concrete and fasten directly then be done with it.

[@carllubrin8518]

I’m gonna do this but into a dojo

[@KINGZSPEED]

You didn’t seal your poly carbonate with foil tape or sealant. The channels will grow algae inside and turn green over time.

[@juliantan290]

Hi Mike, great how to video. Question what is the size or dimensions of the greenhouse? Trying to figure out the rafter length to make sure to fit a 8ft polycarbonate panel? Thanks

[@thefamilyhandyman]

Overall dimensions are 10-ft. W x 14-ft. D x 12-ft. H. You can get more details about the project at www.familyhandyman.com/project/how-to-build-a-greenhouse/

[@Matp78]

Hey how big is this

[@danielwrightson6699]

What was the approx cost to build this? Looking at doing this myself

[@ajjingunia]

was wondering this as well

[@pang-ngiavang1956]

How much was the greenhouse?

[@briangunn21]

Why do you need a tall door when you are short?

[@greglistner68]

What was the total price?

[@brianhoman5682]

Great looking green house. I would love to get one built in my yard. Approximately how much would it cost?

[@dexterdog62]

I figure an arm and a leg, and at least a kidney.

[@davidhayes5382]

About 2000 $

[@tundradave138]

I'm building it now. Looks like it will be $5-6K. I used treated pine instead of cedar for framing and Hardi Board instead of cedar for the knee walls. Also used Gallina polycarbonate panels instead of Lexan, an equivalent product that is less expensive and made in the USA. I ordered 18 sheets of 4x8 panels and used it all.

[@yunoyukki7344]

@@tundradave138 oof thats expansive for that little of a greenhouse.

[@YoYo-yx5gd]

I have the magazine issue of this greenhouse and they said about $10’000-$14’000 depending on material prices. That building it the exact same way with the rock foundation base.

[@spencerliggett3580]

I think I would have had windows and side vents that opened just to aide in the cooling of the greenhouse.

[@keithrayeski6417]

One of the most rugged and well constructed greenhouses I’ve ever seen! Great tutorial that will enable any DIY’er with moderate building skills and standard tool kits, exactly what they need to build a very long lasting and satisfying greenhouse! Now, if I can only keep my wife from seeing this video!😬

[@subhumanrogueminiaturesfor2538]

I might just likely be being abit slow but why are the gable ends double thickness and why the extra beam on the top of wall that fix the roof trusses to rather than directly to one thats already at the top of the wall?

[@markmcmonagle6794]

Could a greenhouse be built on top of a concrete slab?

[@jasminrahman4378]

The best greenhouse. So we'll thought. Do you give out template for someone else to make?

[@jss3018]

Nice.

[@mrshure8984]

Good job, but the wood is rotting.

[@ourv9603]

Well, the heartache of it all is that you can buy a kits for cheaper than if you go down to the home store, select your lumber & fasteners and plexi & build your own BECAUSE we have to pay retail while the factory which makes the kits buy a trainload of materials at a timer and pay wholesale. Even with their markup, their kit will be cheaper. !

[@ajb.822]

Very nice ! I live in nw WI though, and my main uses for it won't be in June/July, when the sun is directly overhead or even a little north. So, my plan has been to have one with a vertical north side ( preferably banked with am earthen berm, but at least insulated &/or a wall of haybales stacked against, held from possible falling by posts, which I then use as mulch and have to replace again in fall). Have a slanted south side to a degree best for maximum winter sun, and have that north-side berm if have one, curve around slightly to protect from wind on each end, or at least the west end ( prevailing wind) ( leaving room to walk out, and let decent light in). Preferably have it in-ground a bit too, whatever is workable without having potential flooding issues inside, and either way, have cold-sinks, under grates or something to walk on, in/ under the walkway. I'd like to also have a sunroom on the south side of a house (am currently renting), I read that that's the best way to have an attached greenhouse but without moisture issues on the wall of your home or whatever. IDK if simply having a plenty of door &/or window opening into it , for air flow and exchange, is all that matters, I'm not very knowledgeable or intelligent on that stuff.

[@chunhowzhuang1809]

羨慕...在我們台灣現在蓋個資源器材室都很困難 因為法令的關係...

[@realityreport79]

Does the sheathing at the bottom provide enough lateral torsion strength to keep the structure from falling over? Modern houses are super strong because of the sheathing but obviously with a greenhouse you cant cover the whole thing. I'm asking because I will be building a greenhouse next spring and I want it to last forever.

[@tombristowe846]

I wondered if a bit of triangulation on the walls, and on the roof too, would be a good idea. Nice job though.

[@tundradave138]

I added wire rope and turnbuckles diagonally from the sole plate centers on the long walls to the top corners at each end. Also ran wire rope from the top plate centers to the top of the trusses on each end to stiffen the roof assembly.

[@realityreport79]

@@tundradave138 awesome, thanks!

[@muffemod]

Nothing lasts forever. BOW DOWN TO THE TRUE!

[@mikeferretti7422]

Who carries polycarbonate sheets?

[@jasonbruce2730]

Why not rebar the retaining wall and set the walls on top of that? That gravel is gonna shift esp when it’s watered. It’s good for a base, but keeping out rodents, snakes, etc is going to be much more difficult.

[@pamelas9]

That was my thought too. Bunnies, mice, and ground squirrels would help themselves if that was my base.

[@mikej9062]

Why the 45 degree roof? Was that a customer requirement? Seems like it will be more prone to wind, a bit more expensive, etc.

[@joannefreeman7799]

What snow load and wind can this design handle?

[@donvance6858]

I was wondering the same thing and can the panels be easily replaced if the snow crashes them in the greenhouse. Can the panels be replaced easily without taking the whole greenhouse apart ?

[@andreataylorschutt3450]

Are we building a house or a green house ? 🤔

[@silentblacknessx8080]

Few weeks to build lmao

[@kongxiong6005]

Lmao. For reals. I Said the same thing too

[@xiezheng3862]

better than the place I live😂

[@jarynelayalavega5840]

Right? Hahahaha

[@GoodL81]

😂 lmao

[@ericredbear425]

The end product was beautiful --- the process felt like a newbie fumbling in the dark. Really gave me a headache, man!

[@Lostinthewoods218]

Very cool! Could you share the name of the vent fan and grow light you used?

[@hadleighnelson1812]

How much would something like this cost to build, not including labor?

[@Bobtony]

Dude woah

[@BrianPellerin]

In another universe, you are a chess grandmaster

[@Mark-id7fq]

Beautiful job! Looks like a $5g project?

[@tundradave138]

About $5-6 K for me. See my comment above.

[@MyBiach]

Are those saddlebags your wearing???

[@hippyhebrewhomestead8593]

A few weeks? Dang how many hours were you working a day? I put the framing for my 8x16 green house up in a day, then the polycarbonate the next, your attention to detail is phenomenal though, great structure!

[@hadleighnelson1812]

How much did yours cost to put together?

[@hippyhebrewhomestead8593]

@@hadleighnelson1812 I picked the materials up when the prices plummeted, I think I was into it about $700

[@olumsezbey]

I want the truck. ❤️

[@rickchen2081]

While the battens look fresh and nice now, I can imagine they'll turn into a nasty shade of grey in just a couple of seasons of UV and rain exposure. Exposed wood on a roof just doesn't make any sense. Why not use roofing screws with washers and neoprene sleeves and screw the polycarbonate panels directly onto the rafters? Hope you at least apply a couple of coats of sealant every two years, which is going to be a major pain now and later if you do.

[@tundradave138]

I used stainless roofing screws with the large rubber/metal washers. Also used H connectors and snap H connectors to join the panels to allow for expansion/contraction. I used galvalume steel building corners for the fascia on the gable ends and the corners of the polycarbonate walls. No maintenance on these products. I eliminated most of the bare wood. Used wood on the knee wall corners as in the video and wood door facings. Hardi Board lap siding on the knee walls. Used treated pine for framing and put waterproofing stain sealer on the knee wall wood corners and the framing just for looks. Hopefully it will retain the color for a few years and not turn the weathered gray in a couple of years.