BUILDING DESIGN SYSTEM

PROBLEM TO BE SOLVED: To provide a building design system capable of efficiently and accurately determining the bearing wall line of a building. SOLUTION: A plan specified by an operator is read from a memory device at a step S1, and the bearing wall lines of the plan are extracted at steps S2 to S7. Determination is then made as to whether the plan contains sufficient walls at steps S8, S11 and S13, and when the walls are identified as not sufficient, wall lines acceptable as bearing wall lines subject to the satisfaction of a preset additional condition is extracted at steps S10, S12 and S14. Also, when the plan is finally identified as not containing sufficient walls at a step S15, a designer is instructed to change a design plan at a step S16.