As our tiny house will be mobile its needs a trailer for the house to ride on. As the weight of the house will be approx 3.5 tonne and bounce around on NZ roads it will need to be strong. The trailer will need to resist wind, rain and sea salt. It also needs to last the test of time. It needs to integrate well with the house in terms of looks and structure.

New or secondhand

There are two approaches, either design and build a custom trailer or find a secondhand one and modify it. Our American friends seem to have great access to suitable second hand trailers and are easily able to modify them to suit. The NZ market is not so plentiful with large utility and car trailers. What's available here is more suited to small home built backyard jobs. Also I have read that with all the extra work in modifying and fixing a second hand trailer it can be more trouble than its worth. Custom built also means you can design it to your exact detail. With the low supply of suitable trailers in NZ I am opting for a new custom build job.

Living big in a tiny house have done an excellent video with Monoway who are specialists in the design and build of tiny house trailers. 

WOF (warrant of fitness)

As with any light trailer in NZ it needs to meet the current safety standards accessed by the warrant of fitness (WOF) system which state:

Width - 2.55m max

Length - 12.5m max

Height - 4.3m max

Weight: 3.5 tonne max

Lights - must have front and rear position lamps, stop lamps, reflectors, registration plate lamp, and direction indicators.

Brakes - running brakes, park brakes and breakaway brakes

Source: VTNZ 

Moving 

As we plan to only move the trailer maybe max twice a year there is no need to own a vehicle that is capable to safely towing 3.5 tonnes. In NZ this means rolling in something like a Landcruiser, Patrol or Discovery which would be cool but not great on the wallet. So I think opting to find someone with 4x4 or finding a towing company is prob the way to go. 

Costs 

I have contacted a number of trailer builders and fabricators in the north island. I have found costs range from $6k to $10k. I have find a couple of local fabrication companies that that can do it but at the higher end of the price range. A lot of this cost is in the brakes, they are around $1500. This may seem like you are not getting your moneys worth when the trailer is only occasionally being used but it is very important and is a must have safety device. 

Protection

There are two ways to coat and protect the metal trailer from the elements. Firstly there is galvanisation which coats and imbeds itself into the metal meaning no rust and long life. My research so far shows the biggest glav dip tank is in Hamilton and it is 9m, so with a draw bar of about 1.5m and 0.5m of clearance leaves 7m of trailer. The other cheaper and more time consuming method is to paint, this is the method used for most huge truck trailers. One issue here is if the the paint breaks down the trailer will start rusting, however this can be prevented with regular cleaning. 

Where to now 

I am working on the design of the house which will define the trailer specifications. Stay tuned as I will show you my design to date.