Open and tall wall construction in a residential house 4

[StrLamp]

hello,
how can we frame the house attached here? the amount of openings is approximately 76% and the middle portion is all open to the full height.
thinking of installing a steel frame, but anchoring the steel posts to the 8" plain concrete foundation is another issue. the house has a long continuous beam in the centre and external walls. Such open concept in a custom home is getting common nowadays. The steel moment frame could be a solution, but the cost is not in favour of the client. is there any way that we can construct the wood framing?

 

[kipfoot]

I think you're on the right track with a steel frame and you may find that the foundation walls need reinforcing and pilasters. If the client wants traditional wood framing, then the client can choose a traditional layout.

Otherwise, the system, and cost, is what is necessary for the architecture.

Communication, as always, is key here and I find that some schematic sketches can help the conversation about what is possible. The sketches may help a client realize that the budget doesn't allow for what they're showing, or it will help them prepare for the cost.

 

[JStructsteel]

I find the Arch that I work with more and more trying to do things like this in just wood. They got called out on it and had to pay me just to design a couple shear walls. Building officials are getting educated and calling out architects.

With that, moment frame is the way to go, they dont have to be huge, and if a contractor building a house like that cant do a competent weld, then you will have other issues.

 

[XR250]

I would try to find some interior shearwalls and then frame this out of wood - 2x8's should work depending on your wind zone.

 

[Ron247]

If your Great Room wall aligns with other exterior walls, you can account for racking with the adjoining walls but in my past experiences, the Great Room wall will be too shaking for out of plane wind loads. I have seen these built out of 2x4 and 2x6 and both are shaky. By time you account for liners at the windows there is not much full height framing left. Check and see how deep you wall studs would have to be to function within the tolerance for stone and brick.

 

[KootK]

If things line up well enough, you might drag all of the in plane shear over to the first story shear wall shown below via a shear truss or some intense blocking. At the second story at least, that bit of roof that continues down is likely to outperform any moment frame with respect to lateral stiffness. That said:

1) That's a long path to detail well in wood.

2) In a prescriptive sense, I feel that is probably not enough shear wall for this size of a wood building unless, per XR's comments, you've got some good interior shear walls helping out.

3) You still have to deal with the out of plane wind flutter stuff. My father in law's house is like this and, under a heavy cross wind, you fear for the safety of the family photographs hanging on that wall. If he could go back in time and make that an 8" wall, I guarantee you that he would.