Rethinking Open Plan

Just returned from a few days staying with my sister in law in Melbourne. She has just built a stunning new "East Coast American" style house in one of the bayside suburbs and we got to talking about open plan living areas.
In the past decade, all my friends who have renovated or built new have done the same thing - a combined family room, dining and kitchen, usually along the back of the house, be it a small inner city terrace or a more expansive home in the suburbs.

As I am planning a new living wing for my country house I am also contemplating how to combine these three important areas.
My sister-in-law, Paula, had the combined room in her last house and found it was too noisy if the TV was on at one end and you were trying to have a conversation in the kitchen. Somehow, because of building difficulties, she has ended up with the same situation in the new house and finds the big room a challenge also to decorate and keep tidy.

The advantage of open plan is that you can be a part of whatever is happening if you are stuck behind the stove. In my farmhouse the kitchen is in a separate room to the living room and I hate being left out of the party while I am cooking!
I am thinking that the solution is to have the option to close off the different areas and to have some sort of architectural separation to make the space seem more intimate.
Here are some houses that seem to have taken on that approach quite successfully.