This paper presents a framework for the automatic generation of floor plans based on adjacency relations among rooms. The adjacency can be generated from user-specified design requirements using a graph grammar formalism. We propose a set of grammar rules to generate graphs that represent adjacency relationships. Our solution overcomes the limitation of previous approaches that generate only rectangular floor plans. We define a set of constraints, such as plan size, room orientation and aspect ratio, for specifying the desired floor plans; and present a set of algorithms for placing rectangular or non-rectangular rooms and for generating non-rectangular floor plan boundaries. We demonstrate that our method can generate varied floor plans from user-specified design requirements. •A formal mechanism for specifying high-level constraints for generating floor plans is presented.•A generic approach for generating floor plans from user-specified requirements as a graph data structure is described.•Algorithms for placing rectangular and non-rectangular rooms based on graph specified adjacencies are introduced.