The kitchen is now one wall instead of having the L portion jut out.

Is the bathroom on the upper level shared by the whole family? It seems tiny for a family of 4 to all use getting up in the mornings, etc.

@LH CO/FL : Yes. And I agree!

Seek competent local professional assistance.

@Mark Bischak : What do see that needs attention? Local professionals around here are not in a hurry.

Can you cover the lower part of the stairwell and use some of that and the landing for a larger bathroom, or additional "powder" room upstairs with just a toilet and sink to help out in the mornings?

Everything. When remodeling or adding on, there is a myriad of existing conditions that influence the design decisions of the addition and remodeling, more than what is communicated in a rough floor plan sketch. Without knowledge of those existing conditions, and other information, it is difficult to professionally evaluate such a plan. If you are questioning the design you have, it may be best to hire a local professional to review the design or come up with a solution.

@Mark Bischak : Yes we do have all of that information as my husband is and has been a builder for many many years. He "knows what's best" and I have anxiety and want to know if there are more options (to toss around) that I may not be able to visualize without collaborating with others aside from my husband. Say... in terms of hiring a professional to review and work on the plans with us, what would the title of said person be?

You missed the point.

Your husband is a builder, NOT a design professional. What Mark is trying to tell you is that you need a design professional. At minimum an interior designer but better would be an architect who specializes in residential architecture. NOT a draftsman. 99% of draftsman have little to no design skills.

I don't think all is doom and gloom because 1), you haven't done anything yet and 2), It appears you have an inner voice telling you there may be other paths to success besides the one your husband has charted. And if "2" is an accurate assessment, you aren't the first to come on this forum with those kind of misgivings.

I'd suggest getting a person of design talent to come out there and have a three, four or five hour design session (a fancy word for that is "charrette") with you, your husband and any other decision maker over your dining room table and at the end of that time you'll have explored options for going forward. I do these all the time and they work well because we're exploring ideas in a highly interactive and dynamic exchange in real time. I wrote about it here Design in a Day | Life of an Architect

Your husband has to be completely on board with this of course. If not, and he in reality is committed to going with what he has, the charrette is going to be a failure. I've been through that with everything being "We can't do that because...." and only leaving what the husband or wife came up with as the desired solution. But that has more to do with "trust" which you all are going to have to have a healthy dose of in your designer for my suggest approach to be a success.

But which ever way you go, good luck with your build. Exciting times ahead!