This is a highly functional design. For aesthetic purposes, I would like to see some gables or dormers on the front attic level. Some features that provide visual separation or delineation between the units would be a nice touch. I really like the deck and the garden.
On the site plan I would raise the units 2 to 3 feet above the street in keeping with the existing topo and to provide separation between public and private space. I would like to find another location for parking that doesn't diminish the use of the back yard for the single family home.