Residential braced wall line offset

[Engin1]

I am working on a 2-story house with a family room wall offset 7ft from the main perimeter wall. The wall height is 21ft supporting roof trusses because it's open on the second floor, the length is 19 ft with window and door opening. Based on IRC 602.10.1, the designated braced wall does not have to align with the wall, so I can image a braced wall line between the family room wall and the main exterior wall to make it offset less than 4ft. And the offset family room wall does not have to be braced panel. Is my understanding correct? Please help and correct me. For 21 ft height, I cannot get the aspect ratio work.
thanks!

 

[phamENG]

A sketch would help, but based on what you've said it sounds like you need to set aside the prescriptive braced wall provisions and come up with an engineered shear wall approach.

 

[Engin1]

See the sketch. The engineered shear wall approach does not work because of the openings and it cannot satisfy the aspect ratio. If my understanding is correct, it does not need to a shear wall.
thanks,

 

[phamENG]

Ah. I see. As long as you don't have any braced wall in that 19'-6" section and you have braced wall panels immediately abutting the open area along that line, then I think you're okay.

 

[XR250]

I would ignore it as long as you are within 21 ft between other BWP's.

 

[Engin1]

phamENG,
Thanks! That's what I thought.

 

[Celt83]

Braced wall panels at each immediate corner from the outset.

Since its a double height space, I'd maybe look at the second floor braced wall line using either the double height or as a ground story with 1+roof above to inflate the required braced wall panel length on that line.

My Personal Open Source Structural Applications:

https://github.com/buddyd16/Structural-Engineering

Open Source Structural GitHub Group:

https://github.com/open-struct-engineer

 

[Engin1]

Thanks for all the comments!