do the sofas and chairs have to stay? or are you open to others?

You can get a larger rug that you can tuck into the corners of the larger couch. This would make it all come together.

is there only the one entrance into the room ( the one off the kitchen?) or a second entrance too? if all furniture is staying and there is only the one entrance, I would put the sofas facing each other and move the chair to the same side as the smaller sofa. pull them in closer to each other, away from the walls. also I would suggest a larger area rug. the rule of thumb that especially floats around houzz is to have an area rug large enough so that the front legs of your furniture can rest on it. It seems to really pull the space together and tie it in. and add some pops of color with throw pillows. if there are two entrances, would you consider purchasing two chairs and having only the large sofa stay? It could be arranged like in the attached file.

heres some area rug options. Im also a fan of solid color shag rugs, maybe a beige, or a pop of olive green

I like the one on the right, thanks!

I would make the fireplace your focal point and I like your idea of having white built-ins on either side of the fireplace. I would place the sofa in front of the fireplace with a large light neutral or slightly feminine rug to balance the heavier, darker furniture if they are staying. The chairs could be arranged on either side of the sofa with room to move in between. I would replace the side table and coffee table with lucite clear tables which will allow the space to feel more open. It looks, in the photo, as if the walls are green-gray, if so complement them with green-gray pillows and throws with florals or graphics. Repeat the white with other accents to tie in the fireplace and built-ins. With the wall and corner where the chair is currently, a side board with storage could be placed here or large floor plants. I hope this helps.

There are 2 openings, both approximately 6 feet wide. Also, the fireplace is centered on the wall. The opening to the kitchen is a little bit off-centered. I think the furniture has to stay for now, and we are thinking of moving the TV above the fireplace once the built-in go in. This is a pic of our old house with the stone and built-ins completed.

The room is 18 ft wide by 21 long ft long with 2 openings (one to the kitchen and one to the hallway)

love the built ins in your old house! so with two openings, try moving your sofa to the opposite side of the other one and see if it blocks the opening too much, or if there is enough space to maneuver around it. if there is plenty of space, maybe there would even be room for a sofa table(not sure if that's the proper name?) at the back of the sofa. its a nice way to dress up the view instead of looking at the plain back of a sofa.

remember that the sofas can be pulled closer to the center of the room.

Try a few things first to see where you want to go with this space. Turn the rug the other direction, place the large sofa facing the FP and the small one facing the windows. Angle the chair between the windows and move the pedestal and sculpture to the present chair location in the corner. The sofas should have their front feet on the rug. I might be tempted to try a square rug in this space. It needs to be wider than the hearth and wider than your large sofa by at least 12-18" on either side.