Thank you for open this interesting contest.
My proposal is give a touch of modern to the building, while maximize the usage of the space.
I have 2 options for the renovation in the layout of the current building, and 1 option for the new building.
For the current building, to make it simple I would propose to minimize the touch in the bearing walls, open more windows for the apartments.
For the new building at the back, it has to symmetric house and it own private garden.
The whole property has a parking with 4 plots.