Make the powder room into a butler's pantry and the layout will work. You may regret having a powder room in use next to the dining room.

Agreed. No one is going to want to use that powder room for anything other than hand-washing. Butler's pantry or even a bar would be useful and help the flow from kitchen to formal dining. That said, what a great house!

HI -- I think everything is good on this floor plan. The extra bathroom is good to have in case you need to have the master bedroom on the main floor someday in the Den (Study) area . The kitchen is not too far from the kitchen. You could trade places with the Den and the Diningroom. Either way is good.

At first look, I also thought butler's pantry but then I notice the actual powder room is a bathroom evidently designed for a first floor bedroom/study. Odd location for that as a powder room. With this arrangement you could close the living room wall it would seem better all the way around to me. You would end up with a first floor study that works as a first floor guest suite. A dining room in this size of house is always too far from the kitchen, I doubt much of anything will change that.

I question the 3/4 bath and walk-in closet between the living room and study. Does the study function as a guest room? If so, doors are needed for the study. If not, the location of this bathroom (with a shower) makes no sense. Are there exterior views to consider? Unless the best views are at the front of the house, I'd switch the dining room and study, with a butler's pantry in between where the bath was. The dining room could be bigger, allow for a very long table if needed.
Laundry room - you might like an exterior door from the laundry/mud room. Move washer/dryer/lockers/closet to the right, put the laundry sink and counter on the same wall. Eliminate the mostly unusable corner cabinet/counter space and then there is room for an exterior door. Or an ironing board.
Consider altering the powder room area. Perhaps the size of the study (was the DR). Maybe eliminate the pantry cabinet and whatever cabinet is shown near the dinette area. Arrange for closet and powder room space in a way to create a hallway (not too wide) from the laundry/mud room to the foyer. This would reduce traffic through rooms. Consider traffic between laundry and bedrooms - more direct route to stairway.
Change the direct opening between the dinette and the laundry/mudroom, for a nicer dinette area, but keep in mind the amount of traffic between garage and kitchen (food in, recycling/garbage out).
Finally, as changes are made, be sure to keep a nice view into the house from the front entry.

Since the door way opens to the hallway and the current dining room entry is all the way around the corner, the location doesn't feel too close to the dining room (assuming the wall has some soundproofing). However, it is in the pass through from the kitchen to the dining room and that may feel awkward if there is constant traffic when you are using the powder room. I like lefty47's idea of swapping the study and the dining room which makes the kitchen closer and the guests can still use the powder room where it is (while the second bathroom can be the alternate choice). It's a great house with lots of space!

Highly recommend not placing the powder room near kitchen/dining. I know this from personal experience, my home has a similar layout. No privacy! I agree have the powder room should come through the laundry room......Should the kitchen island turn the other way? More working space. Loose the angle?

Dining room and living room should be switched. Then you would change the bathroom to a butler's pantry. Since you would be passing through the butler's pantry on your way to the dining room, you could store dishes and cutlery and wine there and have a sink and small fridge and icemaker.

Someone might have already said this, but my head was spinning after skimming through the earlier answers!

Re: the powder room and lack of privacy--have your contractor put sound insulation into the walls of this room. We had the same problem when our house was new, so I upholstered the walls with decorator fabric overtop of a layer of quilt batting, edged with a gimp trim. I did a tented ceiling too! Anyways, all the fabric and padding absorbed sound and eliminated the problem. If I were starting over, however, I'd do it right by adding insulation.

Keep the plan you have, add the extra insulation in both bathrooms as per designer C. Taylor-Luce

I am writing without reading the other comments first (I read after, just to see who I am on same page with). So, here is what I would change around:

1. Kitchen is too far from formal dining room. Do you really want to carry food, dishes that far? Why not swap study with dining room? Move kitchen set up around some: perhaps move cooking surface to island and create opening to new dining room (old study). Perhaps opening should have french doors or pocket doors so you can have a more formal feel when you wish it.

2. Now that study is near front door. I like this since it should be a quieter area of the house. Also, if a real home business gets going it is a good arrangement for clients to come and go since it is near front door.

3. Living room. These seem to be on the way out. Are they used much except for setting up the Christmas tree? This looks to be a great spot for a guest room. Near front door, again for guests to come and go on their own timetable. Has a full bath right there.

Best of all, it is DOWNSTAIRS for visits from aging parents who might not be able to handle stairs, or anyone who has had a ski accident!

Add some french doors with blinds for privacy. Seal off completely access from study (which is now the dining room).

4. Consider moving your laundry room upstairs. This is my own personal pet peeve with my own home. Walk thru doing the laundry. Does dirty clothes, sheets, towels come from the garage? No! They come from the bedrooms! Can you more laundry area upstairs? Or add a stacking washer/dryer upstairs? Or, if not, can you add a laundry shoot to get your stuff down? A dumb waiter to bring back up?

I think a lot of the times the ones who make the plans simply aren't the ones who ever do the laundry!

If you move your laundry, current area would be great area for crafts, wine cellar or dog bedroom!

PS: Once you make the change out with the dining room/ study locations (or another option: dining room with sun room, I like a more casual dining area), then the powder room makes perfect sense since it will be by office.

Actually It is not functional and even dangerous to have to pass through halls for circulation between dinning and kitchens. I would NOT recommend having that 1/2 bath room and instead, I would replace that whole 1/2 bathroom space with a nice passage area giving direct access between dinning room and kitchen. You can have some nice cabinets and counter tops at that space. Also, the half bath (for hand wash and light bathroom use) at a main floor should be easily accessible from living, family, and dinning without having to pass by kitchen. So if I was designing this I would have the bath in place where the pantry is now and keep it.s door accessible from the foyer. The pantry can be relocated elsewhere. To me, A major revision needs be done to this floor plan.