> On Apr 25, 2015, at 11:13 PM, Richard Aiken <xxxxxx@gmail.com> wrote:
>
>
> What I'm considering is pouring inner and outer walls separated by a large gap, chemically sealing the walls inside and out against air/water infiltration, then pumping the air pressure within the gap down toward a vacuum.
>
> Essentially, I'd be building the house as an ENORMOUS Dewar flask.
>
‘
I doubt the increase in insulation would be worth the extra costs (both initial material and ongoing pumping) to beat something like this: <http://www.preciseforms.com/insulated_easiwall.html>.

Cracks in the concrete form earth movement over time would break the vacuum anyway.

The walls are rarely your problem spot for insulation, anyway, given that you put gigantic holes in the things for windows and doors :-)

--
Bruce Johnson

"Wherever you go, there you are." B. Banzai, PhD