The left part of your extended apartment is made by your desires. Firstly, the little room that is between the new apartment and the old one, where you and your wife live, has been furnished for your son. The furniture is elegant and compatible with the naval style, thanks to its white and blue colors, it will go well with striped sheets, curtains, pillows and carpets, and all of the furniture can be colored with tones of blue and decorated with naval amblems, such as anchors and helms(captains wheel). He has a nice bed, which can be expanded when he grows taller, a side table with a lamp, so he can read in the evening, cabinets for storing, shelves which can be placed on the walls in many ways and a table so he can have a computer or do his homework in the soon to come years. The walls are best painted with a mix of navy blue and white (common naval colors), but a lighter blue tone could also look nice, possibly with stripes (naval style) and decorated with pictures and paintings of the sea and boats, and sailboat models on the wall shelves.
We put the kitchen in between the two rooms so that when someone needs to use it they won't interrupt the other. It is placed in the "L" shaped corner and we thought it could be built very similar or even completely the same as the kitchen in the furniture scheme. The room for your daughter is furnished a bit different, with more modern style pieces and it has a trophy showcase for the trophies she has earned, between her room and the common area is a working table and swivel chair for all her needs. The walls are best painted with a light, neutral color, but the furniture is quite modern in design and can go with most colors. The toilet is made humble and functional, with a shower, and space in the lower right corner for a washing machine.
The design is slick and flexible, and the furniture can go well with any style you wish, the smooth, refreshing naval style, or the linear and elegant modern style.