We present a method for designing spine layouts. A spine layout is a layout in which a main aisle is used for the movements between the work cells located on both side and for the temporary storage of work-in-process. Our objective is to find a layout that minimizes both the handling costs and the investment costs. Also, a rectangular layout shape is searched for. With the proposed method, a design skeleton is first constructed with a heuristic. This design skeleton is then optimally transposed into a net layout via an integer linear program. Numerical results for layouts of 12 and 22 cells are presented.