Cold Safe Room

[RobertSmalls]

Originally Posted by skyl4rk

It sounds like the most economical way to do this would be to take an existing room and build an inner wall frame with ceiling and raised floor, and fill the wall space with insulation.

A staggered studwall and 8" of insulation would also result in an extremely quiet room. Here's one room-within-a-room construction built to be extremely quiet: An Anechoic Chamber for SPCR | silentpcreview.com

If this is for a hypothetical cabin, I'll assume it's not a large building. By the time you superinsulate an 8' square room (32' perimeter), you're a third of the way to superinsulating and sealing an entire 25'x25' house (100' perimeter). A DIY solar thermal collector can be built for a few thousand dollars, and would heat the home to comfortable levels without you having to light a fire.

Here's an ice fishing shack with a Trombe wall: http://builditsolar.com/Projects/Spa...arIceShack.htm

[Ryland]

Ridged foam normally has a 15psi compression strength, so one square inch can support 15 pounds, 10 square inches can support 150 pounds, thus you can almost build an inner shell and an outer shell and have ridged foam in between and as long as it was built tight enough you wouldn't need any thermal bridging, so in theory you could get away with studs only at the corners and joints of your sheathing and not have them bridge the entire thickness of the wall.