The description of the influence of electro-mechanical loadings on the macroscopic response of ferroelectric materials is key to the design of efficient sensors, actuators or transducers based on piezoelectric or ferroelectric properties. This chapter details a modelling approach to predict the polarisation and strain response of ferroelectric materials subjected to electro-mechanical loadings. The model relies on a multiscale approach for the description of the reversible part of the behaviour, and on an energy-based approach for the description of dissipative mechanisms. The validation of the whole approach is made by comparison to experimental results obtained on a soft piezoceramic material.