Greenhouses: Who the heck builds/installs them?

[kybishop]

I'm finally getting to the point where I'll be able to put a greenhouse on my property... now if only I could figure out who the heck to call to get one built!

Who builds these greenhouses for nurseries, farmers, etc? I want something a bit higher end: metal frame, very tall (15-20 ft) and polycarbonate, not just a low tunnel. Hoping to grow some dwarf bananas and such that will push up to 12ft or so.

FWIW I'm in the Asheville area of NC.

[brian]

Overpriced contractors.  I think I got a quote for around 15k to assemble a 32x18 kit when I bought mine from greenhousemegastore.com, plus foundation cost which probably would have been another 10k or so.  The greenhouse Kit itself was about 15k.  This was 6yrs ago before costs skyrocketed.  I can't even imagine how much it would cost to hire electrician, plumber, and hvac people to do elec, water, and heating setup.

I ended up doing the entire thing myself w/ friends.  Hell of a learning experience.

[kybishop]

Oof, that's kind of what I'm afraid of.

Maybe I'll just have a carpenter friend do an all wood one if those are the prices I'd be looking at just to assemble a kit.

[Jaboticaba45]

It’s good to do it yourself! Polycarbonate is nice, but at least doubles or triples the greenhouse cost all together. I was able to get large sq ft for good price by saying no to polycarbonate.
It took me and my dad like two months of on and off work to get the greenhouse up. It’s a major job!

[brian]

The kit itself isn't too bad, but contractors will kill you.  Realistically you want water, which means a below frost line trench.   Electricity, which means buried or overhead lines and a new circuit, subpanel, grounding rods.  Heating, which means either propane tanks, natural gas line, or electric heaters.   

If you're gonna grow perennials over winter in-ground, you probably want an insulated foundation, which means an insulated stem wall that goes down below grade a couple feet, which means excavation, concrete forms or masonry block. 

I could easily see this running 100k total to "do it right" if you hire out everything.

The cheapest route would be to build a foundation of something like railroad ties/big pressure treated wood or some concrete blocks.  If you grow in containers you can get away with uninsulated ground/cold floor.  An extension cord or some fat romex or ufb for power... run across the yard from your house.  Heating depends on your fuel source.   A problem you'll run into is with water.  If you just run a garden hose it'll freeze solid in winter, and then you will be stuck running bucket of water from house to yard.  I have been through all this with my last house/greenhouse. 

[kybishop]

It’s good to do it yourself! Polycarbonate is nice, but at least doubles or triples the greenhouse cost all together. I was able to get large sq ft for good price by saying no to polycarbonate.
It took me and my dad like two months of on and off work to get the greenhouse up. It’s a major job!

What did you use for a frame and in lieu of polycarbonate? Is yours heated? I know you're growing some amazing tropicals so I'm just surprised you're getting enough insulation in Chattanooga's cold winters without the polycarb.

I'm really interested in doing a passive solar battery on mine (geothermal vents) to keep it heated on the cheap. I also know enough about myself that while I could probably figure out building one, I'm much better off letting professionals do it It's also very nice to know a carpenter that I can fall back on to build it if a metal frame isn't realistically in my price frame.

[kybishop]

I could easily see this running 100k total to "do it right" if you hire out everything.

The cheapest route would be to build a foundation of something like railroad ties/big pressure treated wood or some concrete blocks.  If you grow in containers you can get away with uninsulated ground/cold floor.  An extension cord or some fat romex or ufb for power... run across the yard from your house.  Heating depends on your fuel source.   A problem you'll run into is with water.  If you just run a garden hose it'll freeze solid in winter, and then you will be stuck running bucket of water from house to yard.  I have been through all this with my last house/greenhouse.

RIP easy greenhouse dreams  I think I can budget close to 40-50k, even though it hurts to even type.

That's all very good to know about water, insulation, etc. I'll be keeping everything in pots except maybe some citrus on flying dragon rootstock that I know won't hog up space, should also keep them less sensitive to cold ground issues. I'm hoping to do a relatively cheap geothermal system for heat to help with that, too.

EDIT: Geothermal inspiration: https://www.youtube.com/watch?v=FWHGlZntDcg

He manages to keep his greenhouse well above freezing all the way in zone 4b!!

[brian]

checking my old emails.... greenhousemegastore quoted me $13k to install a 36ftx18ft steel framed - polycarbonate faced greenhouse on concrete piers (i.e. augered columns like deck footers) in 2016.   

[brian]

[
RIP easy greenhouse dreams  I think I can budget close to 40-50k, even though it hurts to even type.

That's all very good to know about water, insulation, etc. I'll be keeping everything in pots except maybe some citrus on flying dragon rootstock that I know won't hog up space, should also keep them less sensitive to cold ground issues. I'm hoping to do a relatively cheap geothermal system for heat to help with that, too.

You could do it all yourself if you want to do the research.  But think about heating, cooling, watering, etc.  Even if you have a simple greenhouse and simple foundation, you either have to run utilities haphazardly across your lawn or get some trenches dug.  If you don't care about permits you can do the electric easily, but theres no getting around physics when it comes to frost lines

... looked it up... "As of 2014, the frost line depth for the majority of North Carolina is 6 inches"

hah you lucky dog.  It's 36 inches for me.   

Yeah you could probably dig a shallow trench in a day and run all your utilities through it.   I don't think your dreams are dead

Given that your winter lows probably aren't so bad in NC... I'm starting to think you could make this work with electric heat if you use containers.  Geothermal may be fine most of the time, buy you will almost certainly need a backup plan for long periods of cold weather. 

[kybishop]

Oh for sure, it's definitely easier being further south . I think the frost line is closer to 8 or 10 inches here in the mountains, but still that's easy enough. I'll probably do as much as I feel I reasonably can, trench digging included, to save on cost.

[brian]

Assembling the actual frame of the greenhouse kit wasn't technically hard, it was just hundreds of nut+bolts for the frame and hundreds more self-tapping-tek-screws to attach the glazing.  Tedious but simple enough.  I am a big fan of polycarbonate, I think is worth the cost and it looks nice.  Lasts a long time and strong. 

[Jaboticaba45]

It’s good to do it yourself! Polycarbonate is nice, but at least doubles or triples the greenhouse cost all together. I was able to get large sq ft for good price by saying no to polycarbonate.
It took me and my dad like two months of on and off work to get the greenhouse up. It’s a major job!

What did you use for a frame and in lieu of polycarbonate? Is yours heated? I know you're growing some amazing tropicals so I'm just surprised you're getting enough insulation in Chattanooga's cold winters without the polycarb.

I'm really interested in doing a passive solar battery on mine (geothermal vents) to keep it heated on the cheap. I also know enough about myself that while I could probably figure out building one, I'm much better off letting professionals do it It's also very nice to know a carpenter that I can fall back on to build it if a metal frame isn't realistically in my price frame.

I'm using metal frame with wood endwalls 12 ft peak 20x28ft. It's built into the ground. I never thought about frost, but I grow lots of trees in ground and they do great. It's heated with propane heater. Greenhouse uses plastic. Every few years I can just buy more and replace. I've looked into ways to better insulation and I did buy another layer of plastic...I forgot what it's called but essentially it creates a bubble around the greenhouse double layer plastic. Just didn't get to install it last winter.

I'm planning another greenhouse for some other plants and plan to use wood and pvc pipes. Wooden box frame, and bent pvc pipes to make the roof.
That's what my old greenhouse was.

[Daintree]

Heck, who needs a pro builder???
I bought the kit for my 15x20 ft greenhouse in 2009, and my 9 year old granddaughter and I built the entire thing!!





Of course, we have added on and it has more than doubled in size now, with a 20x20 stick-built addition that I built all by myself in 2018. I had a little help from my 3 year old grandson, but really, all he did was hold the can of nails, and get paint in his hair...





Ta da!!!


One very important word of advice - if you have kids or grandkids, do a time capsule in the foundation blocks! If it's a poured foundation, dig a hole.  My granddaughter is in her 20's now, with a child of her own, and she still talks about that!

Cheers,
Carolyn

[nattyfroootz]

I took apart a 50 x 80 engineered greenhouse. Had to call in a contractor friend to use his excavator to lower the trusses and knock out the poles/concrete (part of the deal). Got the whole set up for free, just took me a couple months of weekends to take it apart. Then I practically gave it away on craigslist because its impossible to legal erect a reused engineered greenhouse in my county. Ah well, nice to have spent my covid days next to an old growth redwood field/stream

[elouicious]

After reading this thread- The answer is apparent if unfortunate

You!

[drymifolia]

I hired someone to build mine and regretted it immensely. They didn't have any experience with greenhouses particularly, just home renovations, and they failed to correctly seal all the edges of the twin wall polycarbonate, so now moisture and algae have started to get in the panels less than two years after being installed.

Definitely make sure you seal the ends well!

[hammer524]

I briefly looked into hiring someone and no one in my area really assembles greenhouses/ or I can't find any contractors who do. After I remove a few more tree stumps I am going to assemble my Growers Solution High Sidewall greenhouse/ shadehouse on my own. Ill probably call a buddy when I need a hand.

[Muni]

I suggest going as big as you feel comfortable with a greenhouse. I suggest https://hartley-botanic.com/ even though it might be over your current budget. Perhaps you can find other forms of abundance to add to the money and make it work.

[pagnr]

Mostly I have hoop houses, built with galvanised post and rail clamps, the type for tennis courts or chain mesh fences.
I did recycle an old 12 foot wide glass house, with angle iron roof trusses, into a polycarbonate roofed, but plastic film sided hot house.
Woven clear plastic like solar weave is pretty durable and repairable.
You can also do twin skin " double glazing " for heat retention.
There are also some IR infra red plastic films that trap heat better.

[Tropicaltoba]

I had bc greenhouses build a custom one for me 7 years ago (I supplied the dimensions). It’s actually more of a solarium (I’ve posted a couple of pics in other posts). They shipped it by rail and have delivered as far as Sweden . The aluminum frame and double glazed low e glass (shatterproof for the ceiling) was 30K (Canadian) plus 8k to have one of their guys to come out for 4 days to put it together. Pretty good product, paint started chipping off in one area, and a little problem with a seal over a 3foot area. They were only responsible for the frame and glass, not the foundation or climate control.

[fruitnut1944]

I did most of the work on mine at age 60. That was 20 years ago. 32x54x16ft high. It's not that difficult but did take me 6 months. Cost then was 25K all in. You could do the same now with a few shortcuts for twice that. Cut the height to 12-13ft.

I just helped a guy in CA design his. 30x60x12ft sidewalls, double gutter, solarsoft 80 8mil twin wall everywhere, 25x6ft wet wall, three fans 2x of 36 inch 1/2hp and 48 inch 1 hp, two 80K BTU heaters, $2K controller, two doors. Cost for materials $55K from GH megastore. It's heavy on heating and cooling which is the right way to build something that really works 24/7/365. Cost of the solar soft 80 was about $11K, less than I expected. I think it will be a fabulous greenhouse.

He did a lot of work with 7 builders and GH megastore was his pick. I've thought they were expensive in my past experience but in today's world I think that's a good bid.