Timber Frame Straw Bale Caravan

Hello All,

I am looking to build a straw bale, timber frame caravan (when i say caravan a static caravan will give a good idea). unfortunately where i live building codes are very strict so i wont be able to build a "house" it must be a caravan meaning it has to be moved by a crane and cant be fixed to the ground. this makes the whole design most complicated. just so you are aware this structure will never be moved it just has to be capable of being moved in theory.

the part i am struggling with in particular is the timber frame sill and how to accommodate the straw bales into the design. I want to be able to see the timber frame and wrap the straw bale around. I have a few what i think are solutions to this any advice would be appreciated.

cantilever the floor joints over the sill by about 30-40cm and sit the straw bale on top of that i should be able to put runners down overhung floor joists this would allow for moisture to drain down and keep the bales dry.

make the sill timber massive roughly 30-40cm wide so that the straw bales can sit on top of them completely. i could build a I frame for the straw bales to sit in this would  allow moisture to drain away but make cause issues with insulation as i would have to raise the floor to make a complete thermal envelope.

move the post for the timber frame in of the sill and support it with large foundations underneath. this way the straw bales would sit on the joists and should allow for drainage, but im not confidant with putting the post about 30-40cm in from the sill.

just to be clear this building will have foundations but it can not be attached to them.

if i am in the wrong place and information or direction would be much appreciated.

Also i am on a  very small budget for this so i dont want to pay out for a building contractor and i plan to build the whole caravan myself.

I'm in the process of building a round wood timber frame house with straw bale infill. I wouldn't even think about trying to build such a thing that could be lifted and moved.
To me it sounds like completely inappropriate technology for the task at hand.
Sorry to be negative, but I just think it's not realistic for your expressed purpose.

Hi jamie,

You have quite a project ahead of you and I applaud your decision to build it yourself.  At one point in my life I also really wanted to build my own home.  This was in my pre-Permies day so it would have been a far more traditional home, but i was itching to build it anyways.  All that being said, some tasks might be more expedient to complete by using some heavier equipment--not ideal, but my personal experience building (meaning I contracted it out) my own home was that the whole process was an exercise in compromise.  In particular, I am wondering if you could get a crane to help you out here?

Jamie, I am not quite able to picture what you are trying to build.  Is this house going to have something like logs making up a basic frame sorta like a stick-frame house with straw-bales filling in the gaps?  I don't suppose you can post a picture of a similar type of home could you (just to help us visualize the project)?  I am just trying to be able to give you better feedback.

Regarding building codes, I do realize how onerous they can be.  Several years ago I had a friend who built (mostly contracted, but some actually built with own hands) a partial underground home.  It was actually a fairly Permie-style home in that the heating and air conditioning requirements were fairly minimal thanks to the underground nature.  It did have a forced-air type of a/c, but the heat was all a radiant system built into the concrete slab the house sat upon (the builder was an HVAC contractor so he knew what he was doing), and was powered by one of these outdoor high efficiency wood stoves.  An RMH it was not, but still, not a bad setup.

My point in this is that he also had a difficult time getting the project bank-approved due to building codes.  Eventually he did find a way around these, but it was a major headache.  There was some type of appeal process and he had to explain in detail what he was doing and why.  Specific to his case was the bank would not loan money because it could not find 3 similar homes in the area (comps) by which to judge the total finished value of the house.  A bank loan may or may not apply to you, but I am thinking of all the hoops he had to jump through to get the job completed (and it was completed).

Jamie, this has been a long-winded post, but I would love to understand your project in better detail.  Again, a picture would be extremely helpful if you could add one.  I absolutely love the idea of building it with your own hands, but to offer any further help, I really need to see some type picture.  Do you think you could post one just to help me visualize better?

Sounds like an awesome project,

Eric

Jamie,

I read and re-read your post and did just a little bit of research of my own.  I think I have a better idea of what you are doing.  But first I have to congratulate you on making sure your home will be supported by a good foundation.  

That being said, I think the best idea (and these are just my own thoughts) is to have the posts properly sitting in their own foundation.  Since those posts are going to be the main load-bearing structure, I think that they should rest very secure and therefore need a sort of foundation of their own.  I realize this is more money on a tight budget, but I do think that it is better for the home itself.

I hope this is helpful,

Eric

Eric Hanson wrote:Jamie,

I read and re-read your post and did just a little bit of research of my own.  I think I have a better idea of what you are doing.  But first I have to congratulate you on making sure your home will be supported by a good foundation.  

That being said, I think the best idea (and these are just my own thoughts) is to have the posts properly sitting in their own foundation.  Since those posts are going to be the main load-bearing structure, I think that they should rest very secure and therefore need a sort of foundation of their own.  I realize this is more money on a tight budget, but I do think that it is better for the home itself.

I hope this is helpful,

Eric

The major problem with the project is that it Must be capable of being moved. Which means it cannot be adequately attached to a foundation, because then it can't be moved.
The building materials and methodology don't lend themselves to an even theoretically moveable home.

How big is this structure going to be?

Mike Haasl wrote:How big is this structure going to be?

the structure will be 6.8m wide, 18m long and 3m high

Eric Hanson wrote:Hi jamie,

You have quite a project ahead of you and I applaud your decision to build it yourself.  At one point in my life I also really wanted to build my own home.  This was in my pre-Permies day so it would have been a far more traditional home, but i was itching to build it anyways.  All that being said, some tasks might be more expedient to complete by using some heavier equipment--not ideal, but my personal experience building (meaning I contracted it out) my own home was that the whole process was an exercise in compromise.  In particular, I am wondering if you could get a crane to help you out here?

Jamie, I am not quite able to picture what you are trying to build.  Is this house going to have something like logs making up a basic frame sorta like a stick-frame house with straw-bales filling in the gaps?  I don't suppose you can post a picture of a similar type of home could you (just to help us visualize the project)?  I am just trying to be able to give you better feedback.

Regarding building codes, I do realize how onerous they can be.  Several years ago I had a friend who built (mostly contracted, but some actually built with own hands) a partial underground home.  It was actually a fairly Permie-style home in that the heating and air conditioning requirements were fairly minimal thanks to the underground nature.  It did have a forced-air type of a/c, but the heat was all a radiant system built into the concrete slab the house sat upon (the builder was an HVAC contractor so he knew what he was doing), and was powered by one of these outdoor high efficiency wood stoves.  An RMH it was not, but still, not a bad setup.

My point in this is that he also had a difficult time getting the project bank-approved due to building codes.  Eventually he did find a way around these, but it was a major headache.  There was some type of appeal process and he had to explain in detail what he was doing and why.  Specific to his case was the bank would not loan money because it could not find 3 similar homes in the area (comps) by which to judge the total finished value of the house.  A bank loan may or may not apply to you, but I am thinking of all the hoops he had to jump through to get the job completed (and it was completed).

Jamie, this has been a long-winded post, but I would love to understand your project in better detail.  Again, a picture would be extremely helpful if you could add one.  I absolutely love the idea of building it with your own hands, but to offer any further help, I really need to see some type picture.  Do you think you could post one just to help me visualize better?

Sounds like an awesome project,

Eric

Hello Eric,

thank you for the reply i have attached some photos of what i would want it to look like

as i said this would have to be a cabin style timber frame construction so you would have to be able to lift it with a crane

thank you

Peter Ellis wrote:
Eric

The major problem with the project is that it Must be capable of being moved. Which means it cannot be adequately attached to a foundation, because then it can't be moved.
The building materials and methodology don't lend themselves to an even theoretically moveable home.

Hello,

thank you for your reply, ive read up on the laws here and you can actually attach the home to a foundation via bolts but they have to be removable so the building can then be moved if need be.

yes i do think that the methodology is the wrong one to use because the straw bales are extremely heavy i could make the walls thinner, lighter and easier using wood cladding and a standard insulation.

but i wonder why you come to that conclusion? i admit it was mine at first to but if you have a 100 tonne crane i dont see why it wouldn't be movable?

thank you