This image is terrible. Let us pretend that the dining and living rooms remain pretty much the same (with repairs and perhaps some short "wing" walls between them to separate a bit. The green line is the wall between new stuff and old--just how that will work depends on everything else. But I do want to have a real actual separation here, with doors and stuff. Or at least any permanently opened opening would be towards the rear. The mudroom in the original I think I would like to keep as is (but stick laundry in there--it'll fit fine). So doorways from there would go into the ex-kitchen, garage, and new kitchen. Behind the garage and between garage and house is the new kitchen, family room, bathroom, and small guest room. We're thinking of a more open concept here (hence the erased kitchen), with kitchen open to FR and spare room/bathroom tacked onto the back. (I'm sure our architect can make that work better than depicted here, with an actual roof and walls and better layout.) I'm confident we can work out minor details (like laundry flow) once we get a general idea nailed down... But this concept appeals to us because it puts the noisy activities away from the bedrooms. And since there will be a separation between the old and new, it might not matter about a ceiling difference. The new roof is going to be in a new plane anyway so I'm not worried about it lining up on the outside. I realize this isn't going to be quite as nicely laid out as a new house built from scratch, or if I gutted it and started over, or if I just moved... And if it makes a difference, this house is oriented so that the "good bits" are in the back. It's based on that postwar mentality that the backyard is part of the living space and the front is where the car goes.

Thanks. Your sink doesn't have enough overhang for what we are going for. It was cut on site so there was no error. They say ours is typically what they do but they are willing to come and shorten it a little bit. We want to be able to sweep food particles and whatever else directly into the sink. Your sink has a lip before the sink and I feel like food would get stuck there before it made it to the sink. The majority of pictures online show a sink with countertops like ours. Yours is a postive reveal. We still want a negative reveal just not as big as what we have now. Thanks

@ molewacker Uncouplers were not mentioned as the floor is already installed and the OPs' original question was a basic one about grouting to base board. Yes answered and beat to death. Statements above about cement board being required are completely false. An uncoupler would have been my approach but that still does not eliminate expansion joints although allowing more flexibility. Who was the Architect / Design Build firm that provided the prints with finish schedule for a custom build. That's where the blame lies. Didn't hire one? There's the problem. First you come up with the plan then find a qualified builder to execute them. IMO. Brickwood took a lot of personal time to explain the reasons above.

Using the Bona system with nordic seal will give you the Scandinavian look, eliminating the yellow. It's a pale tan look. Will it blend the new and old? It is a possibility. Are both new and old flooring the same wood specie? Cannot tell from the images. My opinion, the installer laid new red oak and the existing is 80 year old white oak. Difficult to tell due to lighting and the angle of the picture. The installer can try taking more material off of the old floors to see if, they can get down to brighter wood, before applying the finishes.