Looks like a nightmare to add any wiring in an outside wall.

A good reason to ask the construction materials/technique of a home before you buy.

The panels have electric chases built into them (you can specify how many you want placed in each wall section according to the plans). Only downside would be no being able to run additional circuits to different locations later in the life of the wall, but it's no different than running lines through conduit.

Homes constructed with SIPs are"tight" (low air infiltration) homes so you'll need to install either an HRV or ERV (depending on climate) to ensure indoor air quality regardless of whether the insulation is off gassing or not. I like MURUS panels for ease and speed of installation. Best wishes for a successful project.

I'm in 100% agreement with springtime.

if I were building, I'd use sips for floors,

walls & roofline. the best building system

imho.

We considered steel skin SIP's for our build, but it wasn't as DIY-friendly as the ICF we used. You can create wiring chases in an existing wall; I've done it with our ICF. Cut a hole for the outlet, hold a 1/2" ball bearing in pliers, heat it red hot, and drop it on the foam. It will melt a perfect hole straight down through the foam. Cut an access hole below for the ball to drop out, and line it with foil if you want the ball back. Obviously, it only works if there isn't any framing in the way.

I can't imagine that steel SIP's would outgas at all.

Thanks for the input. We aren't 100% committed to this building method, yet. If we do in fact go Timber Frame, SIPS seems to be the only logical option, but pricing is bit on the high side for us, so only time will tell. I do know I will NOT be using traditional fiberglass batting. Most likely SIPS, Rockwool, or Cellulose.