In surface stabilised ferroelectric liquid crystal (SSFLC) cells driven by low voltages,typically below 10V, it is observed that domains of the switched state nucleate and grow, merging to fill the cell. A model of domain nucleation in SSFLCs is proposed, which considers a nucleation site as a local absence of the chevron interface torque. The model is implemented in a two-dimensional simulation of the SSFLC SCE-8 in a chevron configuration with C2 alignment. It is shown to behave realistically over the voltage range 2-10V by comparison with experimental results.