The first floow is siimple and straight forward--qood qualities! Congratulations!

A few constructive comments meant to be helpful:
--What is the room below the kitchen?
--All circulation from living areas to garage (or half bath) must pass directly through work area of kitchen. Is this a good idea?
--The larger house area and the larger garage area create a "tunnel" effect for the area connecting the living-garage areas. Perhaps explore design options to mitigate the "tunnel" on either side?

Good luck with your project!

I would add a hallway, attached to front hall and running between the fridge wall and office so you don't have to go through the kitchen to access the den mudroom, office or bathroom.

Who lives here, and where are you?

How long do you plan to stay in this house?

I ask because, you have a room that could be used as a bedroom as needed for temporary or permanent disability (the room "under" the kitchen). But, you have only a 1/2 bath. It might be well worth your consideration to put a shower in that bathroom so you have a fully functioning bathroom in the case of disability.

I am with Virgilcarter on the tunnel effect and with kirkhall on the need of a shower. There are 2 spaces downstairs that could be used as a bedroom if there is the need in the future.

I am not sure why you have a fuzzy/complicated connection between the house and the garage.
If you want something cleaner, take a look at the attached sketch. Is the same area and I added a 3x3 shower. If you do not need the smaller closet you can have a 5' wide shower.
I did not detail the windows or some of the doors, I concentrated on the kitchen/mud/bathroom area.
I made the garage slightly squareish (same area) to avoid the tunnel up front. It is not as important in the back, specially if you place on that space a porch.

I also show a different stair (wider) that allows a wider office and foyer, just for your consideration. I do not know how this will affect the upstairs.

Good luck.

Here is a link that might be useful: R Redding Home

I don't care for the fact that everyone coming in from the garage has to go through the kitchen. How will the cook feel about that?

Thank you so much for all of the input! I agree with the tunnel effects comments. We want a large kitchen and family room, and then wanted a small office (which is the room off the kitchen) and playroom. I'm finding it hard to fit all of these elements within ~3,100 sq. ft. Perhaps we need to give up a room and incorporate the mudroom/bath/closet into the main area of the house. Thoughts? What do you think of the attached layout instead? My concern with this version was it was not 'open' enough.

I like Naf's first suggestion. Also, in your original/same sq ftage.

Your second plan has resolved the circulation through the kitchen and the "tunnel" effect of the first plan. This plan appears to have some lost space on the second floor where the stairs come up from the first floor.

Have you studied the elevations of the second plan? It appears that the second plan has the potential to be a much more blocky and bulky exterior that the first plan. Not understanding how the roofing will be designed makes it difficult to assess the second floor area above the kitchen and garage.

That said, with good design, you should certainly be able to achieve your program in 3,100 SF.

Good luck on your project.