Buongiorno, I have made few options for your new home, according to possible positions of pipes, mostly. You have options to have more living space or a bedroom plus. Also, you can combine options according to your needs, if you need a larger bathroom or just a toilette on the fourth floor, smaller or a very large kitchen... I think that final design should be combination of rustic details with very clean lines. Old oak or navy oak floors, marble entrance with modern doors and furniture. The accent should be on the stair wall. The fence should be very light, probably of glass, and the wall behind should have different structure from the rest. Stone, designed glass, painting technique or just other colour should be options. It should be well lightned (maybe in the way that is shawn in finishes). The colour sheme depends on your own sensibility. I hope you like it. Grazie