In what region is your flat located?

By common toilet, do you mean powder room? Because the blueprint does not show one. Personally, powder rooms directly off dining rooms are taboo.

My apologies for the confusion. We use term common toilet to refer to one that is not inside any room i.e. just opposite bedroom-2 in my flat layout. By basin I meant wash basin.

is bedroom 2 the one to the right of the dining room? the bathroom there is showing a basin in it. yes? so you want to know, aside from the basin/sink in that bathroom would you also like one in the living room dining room itself. i don't see a need for another one, if the kitchen is right there, and the bathroom is right there... having an additional sink in the dining room isnt something i understand a need for.

Yes nnigrt, you got it right about layout. Thanks for your opinion.

I can't really tell from blueprint, but you might be able to put a wet bar along wall outside of kitchen. You could have a sink, glasses, small fridge, ice maker, etc., for guests to serve themselves beverages. That would provide access to water, a place to put dishes, serve food, and perhaps make entertaining simpler.

Yes Bellamira, I am planning to put a crockery unit along wall outside of kitchen. But I really like your idea of putting sink, too, in it. Thanks.

Initially I was thinking to create a rectangular space by shifting half of wall inside (adjoining common toilet wall - measured as 1500 in layout) and then install sink there.

Wow! If you ran a wet bar/built-in cabinet along the wall with 1900 and 650 feet, with upper and lower modern cabinets, you could add much storage space, a sink, small fridge, even a pantry-style cabinet for storage. Angle the cabinets at the corner that meets the foyer so that you aren't met with a sharp corner. Same at the kitchen doorway.

Best of luck to you!