Vianne is a drifter so when I think of a permanent house for her I need to think of a reason for her to stay. She lived in Andalusia, Vienna and Pavia as she mentioned in the movie.
In Vienna Pavia Andalusia architecture in that time was based on the use of columns and arches including a lots of carving in walls and such.
Knowing that Vianne is unorthodox and is more open to the world than the people in the town in the movie, She definitely needs a modern house where her journey of moving from one place to another ends.
Starting with her character: she loves meditation and she tends to enjoy fresh breeze from time to time. So she needs a high place to sit and enjoy the sea view and the fresh breeze. It might be an elongated balcony or a simple porch extended to the west side of the house( sea direction). In addition, the usage of glass is important. Glass facilitates natural light and opens up rooms allowing smaller spaces to look bigger as well as facilitating a natural indoor/outdoor flow which often enhances tranquility making it a perfect atmosphere for Vianne.
Miss am I moving in the right track? Am really trying to extract info from the movie and am going to post some conceptual models today.