My friend , Tania published a book from Softbank Creative. It is called " Tania no Doitsu shiki Heya Zukuri " means, " Tania's 'How to make rooms in German Style '". I is not just interior book, it is also lifestyle book. She tries to have minimum things in her house since it is psychologically heavy and if it is light, you can manage things easily and simply. I think the concept is similar to Feng Shui , Zen and Ecology.
When she finds things she does not use, she gives away those to Friends or organizations. If you have a chance, please take a look. It also shows her house and her parent's place, which are both beautiful. They are not big, but there are many useful ideas which we can also take in for us who live in limited space.