You should start from the bottom.
So we were sitting a while at the drawing table. Thinking out the dimensions and what kind of space we would be comfortable to live in and what would be reasonable to drag behind our car. The internal dimensions are 145 cm of height, 300 cm of length and 145 cm of width. There is a curve at the front, for the aerodynamics, so the roof length will be a little less. Pinterest has been a wonderful source of inspiration!
Simply because it is a lot easier to build your cabin to match the bottom, than the other way round, we searched for the bottom first. We looked at the secondhand market, to find a proper sized bottom of a trailer in a reasonable condition. That turned out to be a difficult task. The trailer bottoms are not usually made for home built caravans, so they are often too short, and if they happen to be long enough, they are way too wide.
After a long search we started asking quotes from companies to build a bottom for us from scratch. That was not quite as easy as you might think either. First of all, our budget does have a bottom and most of the prices offered were breaking that bottom heavily. Plus many companies only offer a certain sizes and shapes and are very limited the possibilities of alteration.
Finally we hit a jackpot. Helpo trailers near Lommel in Belgium heard our calls and invited us over to make the plans and calculations. A few weeks later we drove off with a brand new trailer bottom, made to our specific measurements (157 cm wide, inside the wheels, 310 cm long on the outer edges), with some additional bits included; an edge to bolt the walls into and a towing hook at the front, for bicycles or buggies. the whole shebang mounted up to a cost of about 1100 euros.
As we had the price for the bottom, it started to be easier to estimate the size of the complete pile of money for this project. After some research, we made an educated guess, that in the end of this our common wallet would be 3500 euros lighter. At this moment, the expenditure has been 2911 euros. With that we have acquired the following:
The walls first of all. The outer walling will be made out of 1,5 cm water resistant plywood, plus some bendable plywood at the front, to make a cool, aerodynamic curve. For inner walls we have softer 0,8 cm plywood with no water resistance. There is also the wood for the framing the whole thing (4 cm x 4 cm studs). In total the cost of the wood went up to 550 euros. Thanks to some bargains. The big plates of plywood are difficult to find in an affordable price. We also put some pennies (90 euros) to the side for the insulation, so that we can be all warm and cosy during the winter too. There is also a pair of windows (230 euros from Germany), since we kind of like the idea of being able to see outside.
Those are the big things for our project. In addition to this, we have some luxury items. Waffle wanted electricity, so electricity he’s got. We ordered flexible solar panels (2 x 100 w) from China for about 250 euros in total, plus customs over here. Belgium is heavy on import taxation for these things.
Then, to get any use out of the solar panels we needed a few additional bits. A solar cell battery for 100 Ah (180 euros). Inverters (16 + 40 euros), we’ve got two, for things with heavy usage and things that are light on electricity. And a charge controller (120 euros) to make most out of the union of our battery and the solar panels. On top of that we have a pile of lighting, leds of course (35 euros) and sockets for appliances, pile of cabling and switches (80 euros of budgeted money for these).
Again we had difficulties to find a nicely priced battery from Belgium. For that we had to look from Germany. The thing to know here, is that you cannot use acid batteries, because of the gases they produce while charging. Or you can, but then the possibility of suffocation needs to be tended to. And the apparent danger of explosion, too. We solved this issue by going for a gel battery, but there are also lithium ones available. Cabling and the smaller bits and bobs are from Belgium, all the rest from China again, but mainly products that are sold also here, just with a different price tag.
There are also already some nice fluffy things for the inside of the trailer, meaning super comfy mattresses (2 x 70 cm wide, 190 euros, from Jysk) and pillows (35 euros). All nice bargains from the Netherlands!
We are still missing a few bits. The one obvious one is the stuff that is going to make it waterproof, the coating. We have been mainly looking at two options; Titebond and cloth, which seems to be a good and cheap solution, or aluminium.
The aluminium is of course the cooler option, but it is damned difficult to find in the size we need it to be. If any of you guys know where in the area of Benelux + Germany and France you can find Aluminium alloy 3001 in at least 150 cm wide, please shout, loudly!
Next time, I hope, I can write already about the actual building of this thing!