Vehicle seat occupant sensor and heater element

An occupant sensor mat (40) configured to be located proximate to a seating surface (34) of a vehicle seat assembly (12). The mat (40) includes a sensor electrode (24) formed of conductive material and configured to radiate an electric field (25) in response to an excitation signal (26) for determining an occupant (16) presence proximate to the seating surface (34). A heater element (28) is configured to underlie the sensor electrode (24). The heater element (28) is formed of conductive material and configured to radiate heat in response to electrical current for warming an occupant (16) residing on the seating surface (34). An incompressible spacer (46) is interposed between the sensor electrode (24) and the heater element (28). The incompressible spacer (46) formed of a material sufficiently flexible for locating proximate to a seating surface (34), and sufficiently incompressible to prevent a substantial change in capacitive coupling between the sensor electrode (24) and the heater element (28) from before to while an occupant (16) resides on the seating surface (34).