Hello! I am trying to add what you want while maintaining the correlations between the additional building and the existing building. I aim to make it looks like a part of the main building itself and also to make it as efficient and beautiful as possible, while also most importantly minimizing costs.
I added a patio to connect the kitchen and living room, and it makes it easier for outdoor gatherings/parties.
For the second floor, it's mainly the same while I only changed it a little that maximize the space that allows for an ensuite bathroom for each room. If you don't want for ensuite bathroom for every room please revert to the base drawings while only adding the master bedroom and bathroom (indicated in my drawings) into the old ones.