Running the twin beds lengthwise against the walls, with headboards against the corners, usually will allow for the most floor space, but the trade off is that it is harder to make the beds that way.

A houzz contributor, not too long ago, had made a wine rack out of 4'x4' wooden pallets, that are used in the US to move a load of goods with a fork-lift truck. Perhaps they have them in your country. He cut them in half so they were only two feet deep and stacked them up to high counter height. The wood would be a nice contrast with your concrete, might add a little warmth to the space. cascio.offsite@gmail.com

I think a comfortable distance between the island and the counter is around 42". It seems that you have only 30" between your cook top and the counter. I might be a little too tight. The wall between the entrance and the kitchen could be 4' long instead of 6', you would then be able to move the island a foot which would give you more room between the cook top and the island. Could you switch the location of the toilet and vanity in your dad's bathroom so your enter facing a vanity instead of a toilet which is a lot nicer.

hi Abhinav, I have a few suggestions. I'm guessing there's a window in the living room. this can be converted into a u-shaped seating space as shown in the sketch along with 2 upholstered accent chairs which will help in achieving a classy look. you can add open or covered storage below the seating. A 4 seater dining table as shown in the rough plan cad sketch can help you achieve both a living and drawing space in the same area. Also, the passage has a wonderful nook that can be used in many different ways. place a winged armchair with an overhead lamp and floating bookshelves along with a simple wallpaper. Or you can also add an 18" wide wall attached counter there with stools, add some funky wallpaper with vintage posters and turn it into a diner! this space can also be converted into a mini Bar! hope this was helpful. cheers!