A half wall between will do it, a bar, a couple of columns, a beam on the ceiling, different paint and floor coverings in each room.

Also a shelving unit which is open to both sides. I'll include a photo from an idea album on HOUZZ below.

And one thing Sarah Susanka recommends is a soffit across the space to divide it from the ceiling plane. Not on the floor, on the ceiling. She uses ceiling height variations to create separation. To great effect I might add.

I'm uploading several inspiration photos to my tinypic.com account, if you want to see more of the photos.

Here is a link that might be useful: MocLan tinypic site

Moccasin,

Which of Sarah's books would you recommend for someone in the design stage of a new build?

Hi, well, I might mention two of them.
Her second book, the one called CREATING THE NOT SO BIG HOUSE, is fine.

But the one I really found interesting, HOME BY DESIGN, has a subtitle, "The Language of The Not So Big House." And it is homes built from scratch, not remodels. Published in 2005.
She has one where architects remodelled all kinds of houses for themselves, and she critiques the features that make the houses better.....but for your NEW DESIGN, I think HOME BY DESIGN is your best bet. It comes in paperback and hardback, same book, available from Amazon.

Or for that matter, your library will probably have some of her stuff. Easy to read and understand too. A good feature I liked about HOME BY DESIGN was she showed a room with the feature added, then what it would look like without that feature.

Hope this helps. It must be wonderful to start from scratch. She says that the site you build on has as much to do with your house feeling right as the house plan does. The house has to FIT the land it will forever be part of.

Yes, I'll look for that this weekend at Barnes and Noble. Funny you should mention that she says that the site you build on has as much to do with your house feeling right. I have really struggled with that concept the last few months. My site is different from most. Most homes are in neighborhoods, and the focus is toward the back side of the home because no one wants to focus towards the street. My home will sit far off the road, with the prettiest view being at the front. So, it's been a challenge finding a floorplan with this orientation. Therefore, I am creating my own plan, that I will finally take to a designer to finish.

Thanks for your input.

CC- The original Not So Big House has really helped me. Are you planning to have a front porch? I can't think of a better way to enjoy your front spaces :)

Also, while it's nice to have open spaces, sometimes it's nice to not have to compete with the TV. In one of her books (can't remember which one) Sarah redesigned a family/great room and took the TV out of the space (except for a small one in the kitchen for watching the news in the morning. The TV area was still nearby, but closed off with french doors...more like an away room. The kids could watch TV in there, but the rest of the space focused on conversation, crafts and fun. It was a nice change and the family loved it! They also had a living room, turned library for the parents' away room. It was a remodel, not a new build, if that helps find the right book.