The brick wall model for ceramics was employed to simulate the dielectric response of 0–3 composites. By applying equivalent circuit method, the effective field, energy storage density and effective dielectric permittivity of the composites were studied. The results indicate that the resistivity ratio between the matrix and the fillers plays a crucial role for all these properties. A composite with slightly less resistive matrix with respect to the fillers favors energy storage and maintains large effective dielectric permittivity providing a useful guideline for improved performances. The low effective dielectric permittivity usually measured on ceramic–polymer 0–3 dielectric composites can also be understood based on our simulation results.