This paper is devoted to the numerical treatment wide electromagnetic scattering scenes by a decomposition into disjointed subdomains to solve time domain Maxwell's equations. It presents a way to adapt existing time volumic scheme in order to simulate interactions between multiple sources and/or scatterers when either computational costs or the accumulation of numerical errors become prohibitive because of important volumes of free-space meshes. This is done by an automatic implementation of the proposed method which leads to a parallel algorithm with an adaptive criterion on the accuracy, introducing by the way some very significant gains on the computational effort. Numerical studies are performed to show the efficiency of this method in comparison with mono-domain resolutions. Improvements of the approximations, relevant of the introduction of the adaptive parameter, are also quantified and then demonstrate their benefits with respect to a straightforward multidomain scheme involving integral formulas.