To add how? It could create a really nasty momentum...

I am not sure. Possibly a knee-wall? I just don't see how this would be accomplished properly.

Building codes require that load bearing studs must be continuous from sole plate to top plate, i.e. no splicing or adding on to the height of load bearing studs.

If he removes the top plate, he can sister the taller studs to the short ones or just start over..

2015 IRC R602.3:

No you definitely can't do that. Depending on circumstances Lvl beams can be used but for the cost..., better to start over.

Thank you RES 3d Sketches. I think he should sister new 9' studs to the 8'. It will cost him more but save from ripping it all down. Plus, I am assuming this would be a win for us because we have more support in our walls. Am I correct?

Show your builder the code requirements, above, and ask him what he proposes to do to correct the problem and meet code...

Add taped rigid insulation panels to the exterior sheathing.

Thank you all for the replies. The only logical thing to do in this situation is rip it all down and start over. I know he is losing time and money, but it's his fault. We lose because our home will take that much longer to be finished. I will definitely show him code.

No...look at the advice from RES.

All he has to do is remove the top double plate, install new, proper height studs and install a new top double plate.

Much less materials and labor time than tearing everything down and starting from ground zero.

I’d have pretty deep clean ncwrns about any builder wanting to create a hinge point in a stud wall. WHY doesn’t he know that the studs must be continuous? And what else doesn’t he know?? This isn’t an auspicious start.

I'd take it apart, reuse the 8' studs for the 2nd floor.

3 or 4 days longer to finish unless the house is massive.

Exactly, my experience with framers that they don't let anything go to waste. They will reuse every single stud and plate. Reframe everything.

Seriously. A GC that would propose a “fix” that wouldn’t pass inspection? WTH is going on with that?

I voiced my concerns and they are going to tear it down and use what they can for the 2nd floor. Getting new 9' lumber tomorrow. Again, Thank you all for your input. It really helped me hold my ground and get the job done correctly.

Make sure you have an independent inspector check every single thing this builder does. The money spent up front for the inspector will be well worth the price to catch the builder's other mistakes and shortcuts.

Personally I would not continue with this builder. Tough nut to swallow now but much easier than what you may have to swallow down the road.

Honestly I have seen and heard of it happening on more than one occasion. It happens, maybe the framing crew is not fluent in English. The part that doesn't sit well with me was his reluctance to immediately tear apart the incorrect wall framing and correctly frame it.

As cp says - you are now going to have to be on him like white on rice. Line up an independent inspector NOW, and pay him / her to visit your home and list code violations, substandard workmanship and a hi / med / low priority fix list on a VERY REGULAR SCHEDULE - and you then have to stay on the contractor.

He's shown his colors to blatantly violate the structural integrity of your new home for a couple of days and some $ - that tells you a lot.

Buckle up.

Been following this. Window location (and possibly size) should be different in a 9' as opposed to 8' ceiling.

Ask friends/neighbors/work colleagues if there are builders/architects who could consult to you at milestones-you can do it privately with your consultant to avoid issues with the builder and just bring up their advice(in writing). If you have bank financing they may also do their own reviews prior to releasing funds and you can bring up if you have concerns.