In this paper, we present Smart Material Aided Architectural Design (SMAAD), the design technique to realize intuitive shape modelling with synchronizing a tangible user interface (TUI) and a 3D CAD system. To realize SMAAD, we first implemented SMAAD Surface, the TUI that imitates the free-form surface. The TUI is a fabric device, in which flex sensors and actuators (shape memory alloys) are embedded. As a designer changes the textile shape using his/her hands, its surface data will be sent to the CAD system through the sensor and a free-form surface can be created in the PC. The operation in the opposite direction is also possible, in which the CAD surface data is sent to the fabric device to dynamically change its shape. SMAAD releases architectural designers from complex GUI operations and visual programming and enables digital model creation through natural manual operations for physical models.