[Strawbale] Strawbale as External Wall Insulation

[james]

I'm continuing to try and find a way to build with bales in Portugal 
that will not cost a small fortune, or give difficulty with planners.

I'm still trying to find registered builders who are happy to make a 
timber post and beam structure.

In the meantime, it is clear that local builders are pretty handy at 
shuttering and putting up the concrete frames we see all over southern 
Europe, and these frames pass the necessary structural/siesmic 
regulations.  20cm reinforced pillars seem to be about €20 per linear 
metre (at least from one quote I saw).

Now, I have read Keven Ledoujet's MPhil thesis and it does seem possible 
to use bales outside a 'conventional' structure.

And, I had been thinking about bales on edge, which would give a wall 
thickness of about 56cm before finishes.

Two-string bales on the large face (ie strings top and bottom) would 
have about 15cm of straw between the string and the edge - is it 
reasonable to notch them 10cm to go around the outside of concrete posts?

That yields the same thickness, in effect, but the bale stack is thicker.

Does anyone see a problem with this, if the concrete structure is in the 
conditioned space?

I'll end up with 10cm void inside the bales.  Any suggestion on what to 
do with it?  Cost is definitely an issue.  Local tijolo is very cheap 
and is familiar to plumbers and electricians for placing services - any 
other suggestions?

I'm quite keen to try to avoid the usual malarky with noggins etc that 
finishing with lime plaster on bales implies.  A possible approach is to 
seal the bales and have a service void and finish with Fermacell (I 
think Larixhaus does that 
(http://www.pmcarchitects.com/blog/homage-to-catalonia-a-pre-fab-straw-bale-passive-house-first-for-the-region/) 
but a 10cm void seems excessive.

James