Using a travel trailer as a greenhouse?

The roll of the dice finds me in the great Pacific Northwest of the US, living in a rented home.  I would love to begin the process of gardening with an aim to being (mostly) self sufficient, but there are two problems: 1st, I have no land.  While winters are fairly mild up here, the growing season is short.  

I often see people selling travel trailers for cheap, if not completely free.  My idea would be to replace about half of the roof with transparent material, and half of the walls (but only the top 4 feet of the wall) with transparent materials.  The parts of the roof that were not transparent would be potential sites for PV panels, so the trailer would not need any external source of energy.  Parts of the walls would be covered with solar hot water heaters, so that I could keep a fairly constant temperature from October to March.

Any thoughts?  I like the idea that I would be re-using a huge amount of resources by using an old travel trailer.

I like your idea of the clear roof.

It seems like I read a thread about hanging shelves along the roof for added space I could not find that thread though I found these:

Joshua said, "Long story short, I'm currently renting my house out and living in an old rv.

https://permies.com/t/72544/thinking-loud-Fiberglass-class-rv

And another:

Travis said, "A friend of mine was paying a lot in rent and decided to do something about it, so he bought a used RV trailer, then built a building around it, and started to make a nice place.

https://permies.com/t/123385/Greenhouse-Nomadic-Living-Earth-Berm

I am looking forward to hear what other folks have to suggest.

There are a lot of "void spaces" in an RV. I have re-habed several, and found those spaces filled
with all sorts of debris from the construction.  They are also great places for mold and mildew,
particularly here in the PNW.

I like your idea, but  I would :
(1) Avoid any RV with slide-outs, these always eventually leak air and water. They are infamous for
getting stuck in the out position, making the RV difficult to move safely.
(2) Strip the interior down as much as possible to avoid mold/mildew issues. Take out all the interior
furnishings, carpets, and paint the remainder of the shell with multiple coats of KILZ or a similar product. You'll
generate a lot of  garbage doing this, with old cheap toxic plywood, fiberglass insulation, and such, so
have the ability to make dump runs.
(3) Make sure that your RV park or rental property is ok with having an older RV on site. A lot of
property owners are familiar with the nightmare of an abandoned decaying RV stuck on their land.
(4) Make sure the model you get has opening windows at both ends, for straight air flow through the unit
to prevent mold and help keep indoor temperatures uniform.
(5) Insulate all the unused spaces and voids with eco-friendly  insulation like wool.
(6) Be able to place the RV for maximum sun exposure through your "skylights"
(7) Have a plan to eventually dispose of the unit. You probably won't be able to sell it. You'll need a way
to responsibly get rid of it.
(8 ) Be prepared for vermin, meth residue, and mold in the RV.  That's all par for the course with free RV's.
You'll want a good respirator/filter when cleaning it out.

Some tools to consider that come in handy for RV work: an oscillating multitool for cutting out furnishings
in tight settings and cutting your skylights, a good shop vac with a good filter,  a cordless caulk gun to save your forearms a LOT of work, a brad nailer and a cordless impact driver for putting up the insulation and constructing the shelves, multiple rolls of contractor bags, a good ladder, some disposable coveralls.

You'll probably be cutting the shelving parts outside, and assembling them inside. Since you are re-habing a derelict
RV, the stairs in and out will be non-existent or rubbish. Carrying wood and materials in and out on those stairs will be unsafe. Take the time to build yourself a small platform stairwell with wide, properly spaced steps FIRST.  

Let us see your finished project and good luck!

I like the idea, but there are a few "buts" to consider.

I think Jeff has given a good heads-up on potential nasties you may encounter.

The other concern I have is weight, and weight distribution. A travel trailer frame is not nearly as robust as a flat-deck frame designed to haul heavy equipment. If you have a bunch of raised beds on the sun-side of the trailer, can it handle the strain? Wet soil is heavy. You may need a bunch of screw-jacks and timbers supporting the frame so it doesn't buckle.

Any place you could park a trailer is a place you could put up a hoophouse.
That said, even if you stripped a trailer down to the deck and built the greenhouse from there you would have the advantage of portability.

As far as weight goes, perlite, vermiculite, peat and coco coir are all pretty low weight.
Supporting the frame in multiple places with jackstands is still a good idea.

William Bronson wrote: That said, even if you stripped a trailer down to the deck and built the greenhouse from there you would have the advantage of portability.

Yes, this catches my eye also. In my northern clime, the movement of the sun through the seasons is quite extreme.

The option of dragging a greenhouse to a spring, summer, and fall location to catch the best intensity and radiance of the sun offers many advantages.

Two things catch my eye! One is Douglass' observation about seasonal changes in the best sun - yes!
The second is in places where the rules are strict about auxiliary buildings, if it's on wheels, you may be able to have it larger, legally.

Reading I have done about greenhouses, reported that anything less than 120 square feet, is far more likely to have temperature extremes that are hard to manage, particularly at some times of the year. The downside of raising it, is that you loose the thermal mass that the ground represents. Finding a way to insulate and "skirt" the base of the trailer might help that. So much depends on the climate.  

I would be prepared to find a way to reinforce the base of the structure, and I agree with the suggestions of extra supports.

It's worth reading "The Chinese Greenhouse" and consider how to adapt the trailer to mimic some of their thermal mass techniques. In my area, having panels I could hold up against the glass roof to insulate it, would be very useful, as an example.

"The option of dragging a greenhouse to a spring, summer, and fall location to catch the best intensity and radiance of the sun offers many advantages."

Yes, in my case, all I would have to do is rotate the trailer slightly.

Definitely support!  

I am thinking about this design and the choices of features in the list of things to put in a 4 season greenhouse:
https://alaskamastergardener.community.uaf.edu/2021/03/26/building-a-four-season-greenhouse/

Snow is almost not an issue at all where I live, but temps do drop to freezing or below, the wind can be quite strong and it rains often.  

Also modifying a trailer to look like this would still maintain the structural integrity of the trailer.

In summary, it sounds like a lot of work, but it will be really cool when its finished!

might be wise to be careful what you put on land that does not belong to you. you never know what might happen in the future

Hi Tom,
I think you have had great answers around the greenhouse portion. Possible, but you may need extra care and planning for it.

I did want to point out that greenhouses, solar, and solar hot water heaters... all want the sun. So if you point that side of the trailer at the sun... the other side won't be very good at whatever else. You would almost need to split it into three sections for all of those pieces.

All of the walls inside, built in furniture and cabinets in campers are where the campers get their strength from.  If you start removing all that you will need to brace the camper back up or there is a good chance it will collapse under its own weight.

I have a 8x16 greenhouse, so about the size of an average camper.  I  think I have 13 black barrels of water in it to try and even out the temperatures in there, It isn't enough.  That much water would be too heavy for a camper frame unless you put lots of blocking and jacks under it.

I would put a skirting from the bottom of the camper into a small trench in the ground.  That way the wind can't blow under and cool your floor and if the skirting was insulation the heat from the ground could slightly help keep the camper/greenhouse warm.

A thick layer of insulation on every surface that isn't glass would help to keep the greenhouse warm at night.  Double pane glass or plastic would help to.  Glass reflects IR and would keep it warmer at night, plastic is invisible to IR and would allow more heat to escape.

Insulated curtains closed at night would help keep heat in.

I have a small insulated double pane greenhouse inside my big insulated double pane greenhouse.  Thermal curtains and a crock pot full of water placed inside the smaller greenhouse keeps the inside 7F0f+ with very little energy use.  Of course it doesn't give me much room to grow plants so it is used for starting plants.  And any heat that leaks from the small greenhouse heats the big greenhouse.  You could consider doing something similar.

I’m in the process of moving all of my plants into an old 5th wheel but I’m leaving the camper pretty much as-is. I do plan to cover most surfaces with  the plastic film that sticks to flooring (like you might see during new home construction.) Best of luck to you in your endeavor!