Looking to add a greenhouse to a 12'x17' shed in my yard. I'm keeping tropical plants and would heat it. Looking for good heat retention for winter. I think double pane [low E?] glass for walls and maybe roof. Size would be about 8x12 lean to style. I see a few online like Sturdi Built that look good but price is around 15k. Was hoping to spend about 10-12k. Any alternatives out there? I'm on Long Island, zone 7.

Glass has the worst heat retention values. The layered polycarbonate panels have the best.

If you are growing tropicals, winter heat is going to be the biggest issue. If your walls and roof don't have enough insulating value to hold the heat, you will struggle to maintain temperature. In an underbuilt greenhouse, heating might become your biggest expense.

I would also not get a greenhouse with a wood frame. Tropical greenhouses are wet, humid places. Wood rots and harbors bugs and diseases. You will have to periodically replace pieces which might be difficult to do without taking down the entire structure. Aluminum is best - easy to clean and maintain.

$15k is probably a good price but doesn't include foundation and flooring, electrical, water, ... Spend the money now. Don't take shortcuts or under build - you will be happier for it 5 or 10 years from now.

Have to disagree with you on r value of glass. Double pane glass with low e gas has an r value of around 3. Poly panels are about 1.7 depending on thickness and # of layers. The problem is most greenhouse makers don't offer modern glazing that window makers do. The sturdy built gh uses a single pane of glass and clear poly on the inside. The real upper end one's call them conservatories, charge much more [many won't publish price, have to get a quote] This is Sturdy built
https://r6h4w9f4.stackpathcdn....
There's one here on Long Island that looks promising but it's pricy [@15k] and something seems odd about. Forgot to save the website will look again.

Here's the other one
http://gardenunderglass.com/
Check out the Solar Envisions Conservatories. They have great r values [for extra$]. Potential problems is if they just sell these i can't find out much the manufacture. Do they only sell through this business? Other oddity. I drove by the business [11 Vanderbilt Pky] and it's someone's home. Had an old greenhouse attached and 2 hoop houses in back. Rang doorbell, no one answered so i left. Seems i have more research to do. One thing i want is a clear view to yard, no diffused panels.

Is low-e glass suitable for a GH? I'm curious about this because we have low-e in our sunroom and even in a south window there my jade plant doesn't get enough sun, nor did a rosemary plant that I tried to overwinter there. (I kind of understand the rosemary plant because the sun is pretty low in the sky here in the winter, but it seems it should be sunny enough in the summer - except for the low-e.) On the other hand, using low-e in a GH seems like it would help keep the heat down without needing to use shade cloth.

I got my greenhouse from Charley's Greenhouse. I just put in the parameters for an 8 x 12 lean-to with 5-wall polycarbonate panels. The base price is just under $13k.

The same greenhouse with double pain glass was over $23k and single glaze glass is $9600.

You are trying to grow tropicals - you want to be happy with your greenhouse and the quality of the plants you grow. Price is a consideration but not the final consideration.

Because my greenhouse is attached to a building (you better check this out too), I had to get a permit and build it to city specifications. For me, that meant no snow load but it had to withstand 130 mph winds.

Low-e windows should not affect the growth of your plants Weedwhacker. BUT, not all low-e glass is created equally. Jjpm995 will have to check the amount of visible light coming through different brands of Low-e. It depends upon the coatings used.

Very valid points, my biggest concern was really high heating bills. I just got another idea. I had looked into this years ago and forgot all about it.
https://www.aquashield.com/
They make a very unusual sunroom. It's a sliding canopy lean to that opens to the outside. I had visited their factory here on Long Island a few years ago and was impressed. It's poly in either clear or double wall [i think triple wall is optional]., not sure if i could go clear walls and triple roof. I remember pricing out at under 10k when i went there. They had the 7'x13' model on display and he said it usually was around 70 degrees in the winter without being heated [daytime i'm sure]. If i get that one i would have to hang it from the side of the shed which would be south facing so protected from the north winds. I think there's a screen option. The fact that their local probably saves me some shipping costs.

Dasiyi, i was thinking because it's under 100 sq ft i wouldn't need a permit. There're other factors [concrete foundation] but i'm not positive about them. I don't mind paying for permits but if it affects my already sky-high taxes it would really hurt. I have an architect coming over to plan for a new roof on my shed. My neighbors 70' tree fell on the roof in the last windstorm. I'll ask him about permits.

Yes, I did have to put in a legal (18 inch deep) foundation. My taxes did not go up because its not considered a living space. When they come for the final inspection, make sure there's nothing in there but plants. No furniture, not even your potting stool.

The permit has to do with the attachment to a structure. I'm not sure sheds would qualify, especially ones with trees lying on them.

Daisyi, this is from Aqua Shields web site
"Do I need planning permission for this type of pool enclosure?
A. Generally not, as the Aqua Shield™ telescopic enclosure is considered a temporary removable structure. Permission would be required for any commercial use, or if the location is in a sensitive area. Please check with your local township for any ordinances and permits you may require."
Not sure if this is a perfect solution but it's an easy install as its mostly assembled. It's a bit unconventional with the sliding walls but that makes it easy to let out the hot air in summer. They claim it tight. Think i'll go back and recheck it out. I like the fact that's it's local.

Sturdi-Built greenhouses are great (at least the one I bought is)
I have glass on the sides with a plexiglass option inside.
Polycarb panels for the roof which hold heat just fine as well as disperse the sunlight.
I am very pleased with the ease of heating this structure.
DM me if you want details.

I had a greenhouse on Long Island from 1980 to 2009 when I moved away.
I lived in the incorporated section of Lynbrook, Nassau County. If it goes on a permanent foundation, your taxes really go up!!!!!!
My first greenhouse was an 8 x 12 free standing one built on a wooden 2 x 6 foundation anchored to 4 x 4's. Wasn't considered a permanent structure by the village.

Daisy is right! Dead right! Growing tropical is an expensive way to go. The heating costs can be astronomical. And look at the cost of energy lately. The cost of building materials. HAVE YOU LOOKED AT THE PRICE OF WOOD LATELY???? It is ridiculous.
I bought a shelf just the other day, a plain 5/8" thick board 6' by 12" wide. Pine $34, poplar $48 and oak, which is what I wanted was $96!!! Ninety six dollars for a shelf. That's crazy!!!
Attaching it on the south side of the house, mine had a sliding door leading into my Dining room saved me about 25% from previous heating seasons. BUT how are you going to heat it!!!! Propane, Natural Gas, Oil??

I can't even venture a guess of how much it will cost to heat it for the winter. Probably a dozen nightmares and there won't be any change!
Please do your research. Please. OVERBUILD RATHER THEN UNDERBUILD!
Tropical plants need to grow north of 60 at night. 65 would be better but more expensive. Perhaps 30, 40 even 50% more expensive then 60. My second greenhouse was a lean to. I grew mostly orchids in mine. Lean-to, 300 square feet, with oil fired hot water baseboard. It ran a lot from Late October through mid March.

Back then it was an old Lord & Burnham double panel greenhouse. Complete project, plumbing, heating, 36" cement block foundation, greenhouse and electric was around 20,000 dollars. It seems to me to build that today I would need, $50,000. Maybe $75,000. Have no idea.

I have no steak in this at all but please research this thoroughly.

My old greenhouse is still up, basically unheated, to 45 degrees at night and my ex's cats sun themselves out there!

Oh I just remembered, on the side of my home it cut my oil usage by about 25%. We kept the house, 2 story colonial at 68 degrees. Yours will be against an unheated building. That will cost you more to heat it, run electric, plumbing etc.

Bill, appreciate your input. A dam 2x4 cost almost 9 bucks at HD, yes costs are unbelievable. What my grand plan is to turn the shed into a man cave hang out [it's almost there]. I have a home gym setup already and a dart board. Last year i put in a small wood stove and have enough wood for a season or two. I was planning to install a heat pump for the shed and use it to also heat the greenhouse. Total sq ft will be about 300 sq ft. On real cold nights i'll run the wood stove. This has been a longtime goal of mine would really like to make it happen. Edit to add NY to Michigan is a strange move. No North Carolina, Florida, Arizona in your future?

In between NY and Michigan, there were 9 years in Florida, 2009-2018. I could not take the heat but the Humidity was worse. At 73, my moves are over. Michigan is about 10-15% colder then LI. My oldest son and daughter are 7 miles away. It is about 20-25% cheaper then Long Island. I have a 900 square foot brick ranch in a Detroit suburb of 90,000 people. Police, sanitation, the works on .6 of an acre. I am pleased to be here.

Keep in mind that a wood stove seems like a good source of heat, it is a very bad thing for a lot of plants. The gaseous by-products emitted will cause problems for plants.

I hate to be a "Debby Downer" but really think this through.
My hope is to inform you of pitfalls that I encountered.
Good luck with your project.

Really appreciate the solid advice. I'm 72 would like to go somewhat warmer but not too hot like Florida. I like it here but taxes are crazy high. At this point my biggest unknown is the heat pumps efficiency. I always thought electric heat was too pricy buy many say heat pumps are the most efficient heat. I have my doubts. It's not a disaster if it's not exactly what i hope for, the shed as a gym has been awesome so far.

Florida was in between New York and Michigan. He probably drove through North Carolina but Arizona would be a little out of the way.

Electricity is probably the way to go these days. Natural gas is becoming a thing of the past. New York City just passed a ban on gas appliances in new builds. Natural gas is really expensive too.

If you plan to grow orchids, they don't do well breathing gas fumes. I do grow orchids and keep my greenhouse above 55. When I first built my greenhouse (10 years ago), I used electric heaters. They worked great but my utility bill went up about $400 a month. I spent the money to put in hydro solar to heat the greenhouse. Now my bill for gas/electric combined for my house and greenhouse is about $150 a month. Ten years on, I'm pretty sure the system has paid for itself a couple times now.

Our house in California (zone 8) had a heat pump to heat and cool our house. Because of the way they work, they don't work when the temperatures are outside a set range so we also had a wood stove. Heating is always going to be the biggest issue.

They say the new 'cold climate' heat pumps are much more efficient now, some working well down to below zero. I'm skeptical though it's too much like a mystery to me. Being close to family trumps the weather for many, although after shoveling 2' of snow a few weeks ago was a workout and had me thinking of warmer weather.

The absolute last thing I would ever do is follow along with any guideline that NYC produces!! If anyone really new, I mean really knew about that place, you would know what I am talking about! That place has been Ba* Shi* Crazy for the last 70-80 years.

I mean it wasn't that many years ago that the Mayor tried to ban 20oz. pop in cups. Now they want to push a vegan menu onto the students. They are pushing policies onto people like crazy. How about just teaching the students.

Lastly, would you like a life changing experience??? Try driving anywhere near that place!! Bring plenty of upholstery cleaner, you are going to need it!

My parents lived for 20 years in NC and then 8 years in SC, so I know a little about those states as well. My sister still lives there. "Nice places to visit but I would not want to live there". I think that's the expression.

But I digress. If I had my choice now, I would not have built the greenhouse. I should have moved away from there all together as soon as I graduated college. You would not believe the traffic. Most of us can't even imagine that many cars and trucks!!!!

But like I said earlier, just do your research, that's all. But I would seriously think about this man cave idea. Honestly. Just my opinion. I don't believe anything is cheap in the NY Metro area. I just talked to my Ex. over Christmas and our little 1,300 square foot home has now a $13,000+ real estate tax bill on a 50 x 150 lot. Can anyone hear afford that??? Can anyone think of retiring and having that as a monthly expense!!! Oh here's one you'll like. No toll booths anywhere in the NY Metro area. That is GREAT!!! But it now costs $18.00 round trip to cross a bridge or drive through a tunnel! And they deduct it from your Eazy Pass. The basic monthly deduction is now $100 a month from your credit card. You must have one to get Eazy Pass. Bridge tolls area more $$$$ if you do not have one. They read your plate # and bill you. When they started back who knows when, it was a $25 replenishment fee. $18 just to cross the George Washington Bridge!!!

My greenhouse was built on top of the garage (same dimension as a standard garage) in 2001 by Florian greenhouse, we have the so-called Geneva construct.
https://www.floriangreenhouse....
It is holding up great after now past 20 years built with dual glass panels.
I would like to address the previously mentioned heating bill. The greenhouse is attached to the house, which is heated with oil, and we have 3 ducts coming from the basement into the garage and up into the greenhouse. Heating the greenhouse is a breeze, my heating bill did not go up much, actually this well insulated glass-box acts as a heat sink and on sunny Winter days the oil heat really only starts kicking in around 5 ish pm /at sun down. It heats the house!
My recommendation would always be to connect the greenhouse to the house and do it properly.