The room is actually 15'10" x 12'9" and I only need a night stand in between. There is no need for a dresser since it is a vacation home and there is a walk in closet. I wondered if there is a comfortable dimension between the side of the bed and wall.

With such a major project, and all the variables to be considered, I would highly recommend that you find a local interior designer who can advise you on the structure of the room, having it wired for home theatre, designing built-ins and lighting, selecting functional window coverings (remote controlled blinds are fantastic for light control), as well as the furniture choices and placement. Since the room has not yet been built, this is your opportunity to consider lots of wonderful possibilities that a professional can suggest.

Ideally, you should have 36" of space around your dining table. This Ideabook has some great tips for selecting the best table for your space. I'd love to know more about your plans. Any photos of your dining room or tables you're looking at that you're willing to share? https://www.houzz.com/magazine/how-to-choose-the-right-dining-table-stsetivw-vs~1344061

What else besides your table and chairs will be in the room? Space for pulling chairs in and out is about the depth of your chair, plus about 8".