Greenhouse: Building a greenhouse in the high desert, 2 by dionosaur

dionosaur wrote:
I am so glad I found this forum!! I live in SE Arizona at 4800 feet, so we get fairly cold in the winter and hot in the summer and I have so many questions!!!

My DH just finished building a storage shed for our yard, he is very pleased with himself and now wants to build me a greenhouse/potting shed. His idea is just build a small shed with large window facing SE and the SE portion of the roof being covered with clear poly panels. But I have so many questions and I need to get information quickly before he starts, as we have already been having disagreements about the design and I need to make sure I know what I want before he gets too far. He is fairly handy, but the shed is the first big project he has built.

First, let me point out that I am not looking to grow large plants or vegetables. I just want someplace sheltered where I can start seeds in the late winter and hopefully overwinter some plants that don't like the freezing cold. I have been doing a lot of reading about greenhouses and it is just making me more confused. Anyone with any experience who can help, would be greatly appreciated.

Here are my questions/issues:
1. I have been reading both, that you need good ventilation, and that you need to keep it sealed? I understand that you don't want drafts in the winter, but with the heat here, I was going to put in windows that opened so I could open them on really hot days to get the heat out. I was also planning to vent the roof peak so it would always let out the heated air and just put plastic over it in the winter. Do you think that will work?

2. The location my DH wants to put the shed faces roughly SE and will get good morning to mid-afternoon sun most of the year. I see most recommendations are for south facing, but as it is being placed next to the shed, that isn't really feasible.

3. We have no power near the shed, so I was looking into passive winter heating. Has anyone had any luck with water as heat storage? Does it need direct sunlight to work? (I was thinking about putting water storage under the plant shelf against the wall with the morning sun, but I don't know if that will work.)

4. The foundation is going to be on wood on top of cinder blocks, but open under the plant shelf area with some weed cloth and wire mesh underneath to keep out the weeds and critters. Will this be a problem?

5. We are building it out of wood, with windows on the top half of the east and south facing walls, and siding for the bottom half and a few small windows on the north and west sides for cross ventilation. Is that sufficient? And should we insulate the west wall? I am so confused.... ugh!

Ok, I think that is enough for now. I am posting a picture of what we are basing the design on, but with bigger windows and a picture of our new shed, which the garden shed will hopefully match in color. If anyone has built something similar, I would love to see it. I know some of you are very creative in your yards and I could use some inspiration. :)

Thanks for any advice!