Most architects wisely run far away from the dreaded split-level project. Beyond being incredibly poorly constructed, these houses pose a series of really difficult design challenges, most notably the uncomfortable near-symmetry and the neither up-nor-down entry cutting between the two wedding cake stacks of the house.
My neighborhood is full of these houses. And increasingly full of really poor additions and renovations attempting to avoid or overcome the house's basic morphology. So, in my first encounter with this kind of a project we have developed the following:
The addition to the south moves the kitchen from the west side of the house to the east and creates an outdoor, covered area in the southwest corner. Below this addition, a much-needed carport is dug down a few feet to shelter the cars. Most dramatically, the house's east face is covered in a series of slightly sloped fixed wood louvers. As the existing house faces the end of a long street, these louvers create a filtered privacy from views and headlights and provide solar shading for new and existing east-facing windows.
This solution of the split-level problem attempts to take advantage of what may be the largest problem of the existing house - the floating nature of the main volume of the house. By changing materials and extending this floating box, the house is simplified into a single louvered wood box. The split-level is then concentrated to become one clean, simple volume instead of its odd, existing appearance of up and down, divided left and right.