Garden Design Ideas

I intend to buy a 5-room HDB in Singapore and wants to design it to have the japanese traditional, natural-like atmosphere by tearing down all the walls and install japanese style sliding paper doors between the walls as different partition and put tatami mat on the floor. But the problem is that I know some wall cannot be tear down, that is all right but is install the that kind of sliding door allowed in HDB? By tearing down so many walls, will it damage the building itself?

PS:I intend to design a small garden at the balcony,,,

I would like to get some design ideas, if you won’t mind!
This is my apartment patio last year in May.

This year I expect it to be at least three time more colored, because I have a new huge planter and I will hang some baskets on the ceiling.
http://a573.ac-images.myspacecdn.com/images01/47/l_b53d5b3082e4c9090cb45c5b4db1884c.jpg