CLT vs SIP exterior wall construction
Caroline Di Diego| Posted inGreen Building Techniqueson
Pacific northwest, 4C climate zone. (asking for a friend)
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About the only reason for either one is for speed of construction. Neither option is cost effective compared to standard stick built.
There is a benefit for CLT for sound especially when it comes to multifamily units.
There is a good thread about a CLT build on the site:
//m.etiketa4.com/article/wolfe-island-passive-building-with-cross-laminated-timber
Yikes.
Is there a third option?
One has integral continuous foam insulation. The other looks nice, and requires continuous exterior insulation.
What are your [friend's] project goals?
CLT can sequester carbon and can cost-effectively replace concrete and steel on mid-rise projects. It can be used for single-family homes but it's not common, or cost-effective except perhaps for some very unusual projects.
SIPs have relatively high embodied carbon, are vulnerable to various construction errors and a house built with SIPs probably won't last more than a few decades without major repairs. But they install quickly.
为了处理一个particular misapprehension you may or may not be harboring:
The R-value of CLT is about 1.25 per inch. Washington State requires a wall R-value of R-21. So if you're relying PURELY on CLT for insulation, as some of the proponents declare is feasible, you're looking at 16 inches (40cm) thickness of solid glued-together wood. I can barely find any cost estimates for CLT, but what I can find indicates that $1000 per cubic meter is a reasonable ballpark estimate. That means you'd be paying about $250 per square meter, or $23 per square foot.
This is much, much higher than you would pay for a cavity wall of any type, or for SIPS, or for ICFs, or for a sane CLT assembly featuring 4"-6" thick panels and some other form of insulation.