With your original pictures - I agree with larger rug. But I don't agree with comments suggesting the rooms are monochromatic. They are lively indeed. I think you are just missing some accessories! Art work on the empty walls - even just a single large dramatic piece is in order. In the bedroom on the white wall, in the living space behind the sofa, in the greenish bedroom behind the two beds. Those are instant areas where you can improve. But I think your spaces are lovely and well put together. Also I agree with the comment about table lamps - some of those would really add something, and your coffee table looks so empty - maybe just one gorgeous bowl, or stack some books. These rooms are 90% done in my opinions, just need a few finishing touches. Some of my rooms come out like this because the clients are not willing to pay for those last few finish items or feel they can do that part themselves...

Somewhere along these lines (with a dark brown rug under the dining). What will your interior look like? (color, floor, etc)

If you do a google search of "Japanese Modern Interior Design" there are some great images that come up as examples for you to see........

Yogender Sharma To make a grass cover, the first thing you will need to ensure if whether the structure of the half basement is capable to holding a green roof. The next would be to waterproof the top again, keeping in mind the soil and the constant contact with water. Once these things are done, you need to locate were it is you want the lawn and ensure you have access to a drainage within or at best near it the area. You will then require the services of a horticulturist to help you set up the lawn. In terms of cost, it really depends on quite a few factors Existing condition of the structure Location Quality of Horticulturist Type of Green Cover etc....