We present a parallel library which can be used for any lattice gas (LG) application. A highly reusable implementation, as well as a general parallelization scheme, based on a graph partitioning technique are developed. We show that the performance we obtain with our approach compares favorably with the plain, classical implementation of LG models on regular domains and can be even better for irregular domains. We propose a theoretical expression for the execution time and we validate our analysis in the case of a specific application, namely wave propagation in urban areas.