In feng shui, Chi or Qi is the energy which one looks into when planning a space. This is quite complex as there are good and bad energies flowing around based on the flow and light of a space, and you respond to them differently. I try to avoid explaining too much as people get caught up with the theory, as this is more about the feel than anything else. My favourite analogy is the feeling you get when seated at the end of a very long dining table in a party, you feel like there is a rush of attention coming from down the table towards you.
People should therefore focus on their senses in a similar way when planning a room, they can really feel these energies if they focus, and place themselves to try to get a feel of the space and how it affects them.
This house by Nendo was heavily criticised for being superfluous with the stairs, but there was a very good reason why they did it, which I tried to explain.
This is really obvious if you are East Asian, and it seems nobody realised this. In Feng Shui terms, this site, sitting at the top of a long road, invites too much energy into the site, while this is good for a shop, it makes the site quite literally unusable for a domestic setting. While In Japan they do not practice the same type of Fengshui as in China, the principles are related. The staircase takes all this energy and swoops it towards the sky, keeping the rest of the home calm and protected.
The staircase in a very purposeful way, directs the attention from the street away from the calmer living areas.