Putting a trailered tiny house on a foundation

Hey, all! I have a 24 x 8 tiny house on a trailer. The city says I have to put it on a foundation or move it. I'd rather put it on a foundation, and I can probably afford to build the foundation. I'd like to just set the entire existing structure (steel frame trailer) on top of a foundation and bolt it in place.

Here's the question: how? Short of hiring a large crane (prohibitive), how do I engineer the process of getting an existing structure in place on a foundation?

My best guess so far has been this:
1. Pour footings up to grade.
2. Pull the trailer in over the footings and jack it up with several inches of extra clearance.
3. Build up with concrete blocks everywhere except where the jacks are.
4. Lower the trailer onto the new block wall foundation and remove the jacks.
5. Fill in the jack gaps with blocks / poured concrete.

I don't know if that would meet code, and I don't know if there's another approach I should consider. Your advice would be appreciated.

You might want to ask the inspector for guidance. Be sure to keep the conversation positive.

If this were my situation I would put the trailer frame on four to six jacks.

Then I would remove the tires.

I would enclose the lower part under the trailer.  There are special products that you can get or your idea for using concrete blocks might work.

Last enclose the trailer tongue so it does not look like a trailer tongue, maybe a planter box.

I am looking forward to hearing other idea.

Hi Jared,

Oh yes,   Welcome to Permies.

I forgot to add that sometimes the trailer tongue can be unbolted and removed.

I agree that the first step is to talk (nicely) to the inspector. What is structurally sound and what meets local code have little to do with each other.

Jared, it might help if you give us some indication of what ecosystem you live in, what sort of ground you're dealing with, and what sort of storm risks are likely. I like Anne's suggestion of removing the wheels and inclosing the tongue to disguise it (maybe a tool shed?) just in case you feel there's any chance it might eventually need to be moved.  In many ecosystems, I'd be looking at how to insulate the foundation to help keep the house warmer in cold weather, and cooler in warm weather. Tiny houses are easy to heat due to their small size, but also generally have no thermal mass to help with temperature swings. Adding insulated thermal mass through the foundation work might be a long term asset.

While under there, some good floor insulation could be added.
Could the whole unit be sat on jacks with concrete pads, anda wall put around the base to remove the trailer look?

Glenn Herbert wrote:I agree that the first step is to talk (nicely) to the inspector. What is structurally sound and what meets local code have little to do with each other.

This!

The rules vary wildly for mobile homes, from simply tying them down to prevent them from blowing away to fully removing the axles and tongue and building a concrete block crawl space foundation.

R Scott wrote:The rules vary wildly for mobile homes, from simply tying them down to prevent them from blowing away...

Even if you want to keep your trailer mobile for eventual relocation, there are lots of good ways to tie them down, and yet far too few people do so. With weather weirding all over the place, failing to do so can result in dead people and I always consider it bad enough if someone kills himself, but if his trailer crashes into a neighbor's and a child gets killed, I wouldn't want to be the one with that on my conscience.

I've often said on this forum - build *better* and *smarter* than the codes! Be the one whose house is still standing when the hurricane/tornado/earthquake... has done its best.

Thanks to everyone who has weighed in!
I completely agree about keeping conversations with local officials cordial and on trying to make the final product look good and be well insulated.
I'm still not sure how to engineer the process.
Option 1: Jack up the tiny house high enough to dig & pour footings & build foundation, then lower the structure into place.
Option 2: Move the structure out of the way on its existing wheels, build foundation, then somehow get it back in place.
In both cases, I'd need some clever engineering to connect the steel trailer frame to the foundation as well.

Are sonotubes or micropiles acceptable foundations where you live? They tend to be cheaper than a traditional foundation. If they are, put in a couple extra for a deck at the same time.

If you aren't putting in a basement, it's also nice IMO to have access underneath for later and that might help you with removing cribbing and jacks to put it into place. Many people finish around the bottom with something like wood or vinyl to block the wind and critters but that isn't strictly necessary.

If Sonotubes/micropiles are common where you live, your inspector should know how code wants them to be attached. I wonder if you could treat the whole trailer frame as a rim joist?

Not sure where you live, but your current foundation plan with the blocks. wouldn't work anywhere with frost heave- the blocks on bare ground would be a problem and shift.