If by "temporary" you mean one you can put up for use this winter, then take down, presumably for summer storage in spring, then the only practical type I can think of would be one of those clear, pop-up GH tents, which would be a real bear to try to heat without wrapping it in so much insulation it wouldn't admit enough light to make it worth bothering, as opposed to just setting up growing space under lights in a heated garage or a basement.

Otherwise, your next level up would be a polycarb glazed one, and from what I've read on this forum, only you can decide if you are willing to put the time and effort into getting one up, then disassembling it in just a few months.

Or, and this may sound screwy, but might work: TWO tent style pop up GH's, one enough larger than the other for it to provide an air barrier for the smaller, set inside the larger.

Then, a vapor barrier for the floor, with some matting to help insulate it. For easy storage, the small sponge foam mats available at Sam's Club and most home centers, with jigsaw edges that hold them together, then come apart for easy and lightwight storage. They might be ideal for your purpose and also, help keep your dad's feet warmer and give him a resiliant surface to stand on, both important for someone his age.

Just a possibly cockeyed notion, but one inspired by the double walled plastic commercial GH's that use air to insulate. Maybe it could work on a small scale. I honestly don't know, but they are cheap enough, and now with so many on end season sale, it might be worth a try.

Thanks birdwidow.

I was planning on a polycarbonate greenhouse to put up and take down in the spring...work yes, but I have 2 boys to help. My corundum is that it is in a spot that doesn't receive south light. Am I better off paying for a polycarb greenhouse kit and insulating the sidewalls basically leaving the roof for light, or am I better to build fully insulated walls with 2x4 construction with a poly carb roof?

There would be a lot more work than you might imagine, because one of the things necessary for just about every polycarb GH on the market is lots of tubes of silicone sealant and from some of the posts on this forum in the past, taking most of them down is more work and mess than getting them up.

Constructing walls of wood studs is easy enough, but if you want to reuse it, I believe you would need to build it with fitted joints and perhaps even threaded sleeves for bolts, instead of nails, at least where each section joined, to allow you to disassemble it without wrecking it.

What about using Type 250 foam, set into frames? It would be light, yet pretty sturdy, and self insulating. But you would still need to cob up someting to serve as a deck for a polycarb roof.

There is one other possibility, perhaps worth your looking into it.

If you have the financial wherewithall to buy one, you might check out a small Solexx GH. From what I've read about them, they are already insulated, and have far fewer parts to them. Their 8 x 8 size is supposedly light enough to be picked up and moved. They describe it as portable.

There is one currently listed on eBay for about $850.00, shipping included, but you might find an even better deal with a websearch.

If you do decide to just buy a mfg. GH- tis the season. Then, wrap it all up in a solar pool cover, and have both light and pretty decent added insulation, even on the north side and with a large enough cover, you could just double it on that end.

For what you want to do buy one of those little portable greenhouses.
I had a 6X8 that I bought for $99.00 including the benches and I used it for two years.
The worst thing about them is the zipper on the door is fragile and they are hard to keep from overheating on a warm sunny day.
I used two 1500 watt heaters in Jan. just one heater most of the time.
When I had my portable it was 15F or less nearly every night for two weeks in Jan and it cost me about $30.00 a month to heat it
In the real cold weather I inserted foam board between the tubular frame and the vinyl both on the wall and the roof.
This was removed on the south side every morning but since your will be against the house you could leave it in just pull the piece out of the ceiling.
This is sure not ideal but for your situation it is about as good as you are going to get and can be taken down in about 10 minutes.
For the thousands of dollars you save over buying a GH like most of us on this forum have you can afford to spend 30 bucks a month heating it.
I now have a much larger and well insulated GH and it cost me that much a month to heat it and some are spending a lot more on the large ones.
You will need some florescent grow lights due to the location.

Gman29:

Gardener and I seem to be on pretty much the same track, although I stll think that a wall of air between a small pop-up erected inside of a larger one might make heating the small one a lot easier.

But he is right about one thing and it goes along with what I have stated here previously: given enough BTUs, you could sleep in the nude in a tent at the South Pole in winter, and stay warm. The real issue is the cost of providing the BTU's.

It's really a cost-benefit thing, like my thinking of using a portable AC in my GH for a short time in summer. Even if we had a place to put an addition onto the house, between the cost of it and the increase in RE taxes as result of it, paying the electric bill for using the AC still wouldn't begin to equal the cost of the addition & taxes in my remaining lifetime, and I'm exactly 20 years younger than your dad.

I know this is late advice, but I purchased a portable car port at Sams club for only $190 and put 6 mil plastic cover on it to be my greenhouse. I could not afford a real greenhouse like everyone else and had to improvise on it. I can take it down and put it up again anytime and without having a lot of expense. Also, I have plant grow lights, a power cord extention line and a small fan to do operations in my new "greenhouse" to cut other expenses of heating and cooling. I only had $450 to work with and built my tables out of scraps at construction sites. My next project if solar power panels. There is a converter kit and solar panel at a warehouse here for about $400. and it is said to be able to run a computer system. I don't think it would be enough for running a heater but a fan would definitely work on this.

For a few dollars more you could have bought yourself a 12X10' HFGH.