[Greenbuilding] An Euro-shade of Green: Seven Storey Wood-framed Strawbale PassivHaus social housing

[RT]

n Tue, 21 May 2013 11:33:10 -0400, Sacie Lambertson  
<sacie.lambertson at gmail.com> wrote:

>>        http://tinyurl.com/k8qlkdk  (links to André's pix of the  
>> 7-storey SB)

> Really unattractive building.


The building has only gotten as far as the structural frame still  
surrounded by scaffolding and already she poo-poos it as being  
"unattractive" ?

Sheesh! Wymmin eh ?

Like my 10 year-old nephew exclaimed one day when he was particularly  
exasperated with his Mom:

  "Women ! Can't live WITH 'em ... Can't live WITH 'em."

(Presumably an aberration/childish misinterpretation of the more common  
utterance heard emanating from exasperated men worldwide).

But a little more seriously:  I'm having difficulty seeing the supposed  
Green-ness of the design choices.

I haven't investigated the pros & cons of CLT panels but they just look  
like a profligate use of wood to me in this application.

And those plywood-encased SB modules make me wonder why they even bothered  
using straw.

Why profligate ?

Whether in axial loading (ie compression resistance) or flexure (ie  
lateral bending resistance) , over 90% of the wood in the CLT panels isn't  
doing anything except maybe contributing to increasing the dead load.

What if, instead of the CLT panels and plywood-boxed straw modules, the  
two separate elements were combined so that the walls were box beams 400  
mm in breadth, maybe with open web trusses as web stiffeners as required  
(say 800 mm o/c or more for say, 38 mm thick webs)... with say 400 mm wide  
by 150 mm deep LVL beams as the top and bottom chords ? (ie ~ 90% (WAG)  
reduction in wood volume consumption and reduced thermal bridging  
potential)

The resultant wall panels would certainly be a lot stronger than the  
current design.

And then blow the cavity of the box beam full of straw ( similar to the  
way that farmers blow hay and silage into barn mows) instead of (as shown  
in the video) stuffing string-bound bales into plywood box modules then  
cutting the strings and hoping the straw somehow fits itself around the  
internal 20mm x 20mm cleats (not likely to happen, resulting in  
R-value-lowering convection in each and every module).

ie I'm guessing that in France as in North America, small,  
labour-intensive rectangular bales have been abandoned by most farmers in  
favour of giant round bales. If one is going to industrialise the process  
of building with straw then it would seem to make sense to utilise  
industrial bales  and to do that, it would mean simply rolling the straw  
off of the giant round bale into a hopper feeding a blower to dense-pack  
an insulation cavity.

And that clay tile cladding that is shown in one of the pics. What is  
different about the embodied energy numbers for that clay (presumably  
fired in a kiln) as compared to fired clay brick ? (Clay brick being  
almost criminal on the embodied-energy scale from a strident Greenie's  
point of view ?)

But of course, easy for me to critique from afar and without any real  
number-crunching to back up the crit.
(I'm just trying to keep André happy by throwing a few francs into the  
discussion)

On Tue, 21 May 2013 11:49:55 -0400, le $#!+ -disturber André a écrit:

> Bonjour mon ami,
>
> Good to hear from you. You being quite silent of late on the GSBN I was  
> wondering if maybe [snip]


[dusting off hands] My work here is done.

-- 
=== * ===
Rob Tom					AOD257
Kanata, Ontario, Canada

< A r c h i L o g i c  at  Y a h o o  dot  c a  >
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