Sounds great, Billie! I'd go for the 2' wall around the edges - whole bunch of reasons - the plastic stuff will 'move' with the heat, contractions, wind, and so on, and it wouldn't do well against concrete. Insulate the wall.

Watch out for condensation in the winter. This can be huge - so keep that in mind with rain troughs to funnel the water running down the glass away from stuff that rots.

Heating isn't the big issue, cooling it is. If I had it to do over, I'd invest in several of those automatic, non-electric temp sensitive vents, at least one per every 3 foot along the top. Trust me, the first time you don't manage to open up the ventilation and all your plants are toast because its 135º in March in there, you'll wish you had popped the extra money.

For further cooling, they sell sun shade cloth that can easily be bungie-clipped over it - we put it up all summer, and are about to take it down now.

Heating, well..... it can be expensive. You might not need that much -I use an electric heater thats set to go off at 40º, it might go on a few nights in the winter.

Can you dig out and go deeper? Several of my friends have ones that are 3-5 feet down in the ground with steps down. It gives them a longer growing season as it helps insulate. They also have gravel in the walkway to help drain water and also works as a heat sink. They have cement beds on front and back that are raised some that also act as a heat sink. They are well ventilated. One has a solar fan that moves the air. Wish I had one like that!

You could go either way, Billie - down to ground-level or with a wall. That is, I've done both.

Right now, the south wall of my greenhouse (a sunshed) extends nearly to the soil. After plant starts are out of the way, the front "table" (really, really low table) is carried out in 2 sections and a bed of basil is planted in there for the Summer. The basil is still alive in there right now despite frost nearly every morning. Can't be growing but it's alive.

Years ago, I had a lean-to against a garage south wall very much like you are thinking of. That had an insulated stud wall to 30 inches. That was just the right height for a long bench for flats and potted plants. Above that, I could put hanging plants.

Either way, I'd be disinclined to heat the greenhouse in the Winter. It's just too expensive and, you've really gotta think about the commitment to Summer growing. Prime Time in the greenhouse is late Winter & Spring, of course. No vacations at that time of year - - you may as well move in with the plants.

digitS'

david52 - I have been looking at the auto vents. I have to do some calculations as to how small I have to make the windows so that the auto vents will lift them. It looks like 1'x 2' is probably the biggest I dare go. I was thinking 3-4 in the roof, two on either end and two on the front on either side of the door.

margaret - I don't have the extra cash right now to build a wall that would be 3'-5' down, althought I love the idea. I may be able to go 1'-18" since the soil is pretty soft there, I worry about shifting, so the footer would have to go down some. When they build our new house, that area was completely excavated, but the other problem with going down is the house's water heater access is going to be in the greenhouse. I don't want to have to lift a new one 4'-6' up to install, Yikes. But we want the water heater in there because we have had some freezing on the lines (poor design, nothing we can do, all the manufactor's issue, Karsten).
If I can make this first greenhouse work for me, I might in the future (way distant future after I win the powerball) try to build an underground greenhouse. I have been doing research (part of my dreamers therapy LOL) and they look so cool. Plus it would be really neat to be able to go and pick fresh tomatoes and peppers in a blizzard.

digit - if we have anymore storms that knock out the power, I may move into the greenhouse anyway. Glad to hear that you had success with both set ups. I wanted it set up there to help with the water heater problem and put it out of the wind. We had 40 mph sustained the last few days, I hibernated.

Im glad to hear you all pretty much agree that thare is no point in heating it.

I forgot to mention in my origional post that these panels are 1/4" thick and weight 48 lbs. each. The track is from t-slots, item #TS10-10, the first item on the page the link takes you to. I don't think I should have a water problem with the rubber gaskets they have, but it is Colorado and I have never used this product before. I will probably add gutters later down the road, like when I put them on the barn.

I have a few more greenhouse books to pick up from the Bookmobile today, so I will keep you guys up on what I am thinking about. I am excited if you cannot tell. Please give me any ideas, as since I am planning first for a change, everything is welcome.

Billie

Here is a link that might be useful: T-Slots

Sorry I made an ID mistake. The T-Slots braces I have are TS15-15L (pg 10), not TS10-10.

Billie

You know, Billie, you could probably make that water heater do double duty and heat the greenhouse, also.

Probably not a good idea but there ARE greenhouse that use hot water heat - not steam. I think you've probably got the technical know-how right there at home. Is it a natural gas unit?

The aluminum you are intending to use looks like it should hold 48lb panels. Gosh, those are heavy!

I can remember the 1st greenhouse built with aluminum in the range where I used to work back in my salad years. We joked that it was put together during a windstorm because nothing was square.

The Lord & Burnham greenhouses built while I was there were a great improvement over that 1st house but it was kind of sad to see the old wood structures taken down to make way for modern construction. Heck, the LAST wood greenhouse to go had glazing bars that had been cut on-site using tamarack boards with a table saw. The thing wouldn't have been coming down after 40 years except that this HUGE aluminum greenhouse was built right over the top of it (& the 2 little houses next to it, circa 1920's).

digitS'

The condensation issue occurs on really cold nights, like Early on a really cold morning, I'll go out there and its raining.

Of course, the fewer plants you have in January, the less this is an issue.

A couple other things to consider.

When you put in the cement footers, use 2" styrofoam board on the outside to help keep the ground frost out of the cement and keep the green house and soil warmer. Also consider raising the soil outside against the foundation to near the top to provide additional protection from winter cold.

For venting, be sure to have windows/vents into the house that you can use in the winter--no use running the furnace in the house while you vent the free heat from the greenhouse outside.

If you can, run a freeze faucet through the wall of the house into the greenhouse so you don't have to haul buckets of water and don't have to worry if it does freeze.

We have a 8 x 16 sun room built onto the south side of our house. A bit different than you are contemplating as it is standard construction like any room on the house, except it has massive windows that run nearly from floor to ceiling on the east and south faces (west face is the old exterior wall of the entry porch). Because of this, the room is well insulated and the roof overhang is designed to allow full mid day sun all the way through the room (and half way or more up the back wall) in winter, but as the sun gets higher in the sky, the eaves block the sun so there is no sun actually coming in during the summer except through the east windows at sunrise. This keeps the room from heating during the summer, but it really heats up in the winter. We left all the old windows in the old south wall of the house, so in the winter we open the windows to the living room a couple hours after sunrise when the sun room temp gets to 70 degrees, then let the room keep the living areas of the house at 75-80 degrees all day long. At night when it cools down, we close the windows and the sliding door from the porch that provides access and the temps fall into the 50's to low 60's at night. Since the windows and sliding door aren't closed real tight, we get some leakage of heat from the house, but the room still cools down quite nicely so we don't feel we are losing too much heat at night and gaining quite a bit during the day. Occasionally during -20 to -30 weather the room won't heat up enough during the day to open things up again and on those nights we will leave the sliding door cracked a little to make sure it doesn't freeze out there.

I start my transplants in the room in the spring as they get lots of sun and light when small and mid-day shading just before they go out. During the winter the room is filled with geraniums and amaryllis for color. We don't use it in the summer other than to let the amaryllis grow out because everything is out in the garden then.

We also painted the interior walls of the sunroom, the old south wall of the house, a dark green to make it attractive but absorb as much heat from the sun as possible rather than reflecting it.

Good luck with your plans!

digit - the water heater is propane. I was thinking just the fact if it "sharing' the space would help keep the greenhouse from freezing. Were you thinking the same, or something entirely different?
Tell me about they are heavy, there were 4 of them on a 2x4 and plywood pallet that my husband and I though we could carry the 20 feet from truck to "jobsite". Almost, but not happening.

david - thanks for the tip on the moisture issue. I planned to use foam sill seal between the foundation and framing, I think I will add a roll of Moiststop or Vycor to the list for the top of the framing. That is the stuff they use between the house framing and the windows at install, black, tar-ry and resists water well, actually completely. I plan on keeping my potted herbs in there through winter as my kitchen table is really crowded.

beeone - thanks for the reminder about covering the concrete. The foam board is a great idea. I have a bunch of 6" thick I will make sure I use for that purpose. I collected it for insulation for some cold frames I still have not gotten around to building. Those will probably happen in December after a few other chores are complete.
We thought about cutting out our 4'x2' bedroom window to go in and out of the greenhouse, but have decided against it for now because of: time, money and permits. We don't have to pull a permit to put up a lean-to, but the doorway would make it an additiona and opens up a whole 'nother can of worms. Might happen if I hit the lotto tonight though. I know a few contractors that could use the work, LOL.

As far as water goes, there is a spicket right outside of where the greenhouse is going anyway and my kitchen is only 30 feet away on the lea of the house, so water access is not a problem. In the winter I have to haul warm water to all the animals from the house, so it is not much of a difference. Besides, if I get desperate, I can just open the spicket on the water heater, LOL.

Thanks for the help. Keep those ideas coming, all are appreciated.

Billie