Frame-based Gaussian Beam Shooting is presented as an alternative to ray-based methods, when reliable and accessible knowledge of propagated electromagnetic fields is required at all points in built-up environments. This communication presents a general Gaussian Beam Shooting algorithm based on paraxial beam tracking complemented with the use of "image" frames and with frame redecomposition on reflecting surfaces, to account for the presence of ground and buildings. Numerical results obtained in the case of a "single wall" and of a "parallelipedic building" are compared to Parabolic Equation and FEKO software results