A numerical method is formulated based on Finite Elements, Isogeometric Analysis and a Multiscale technique. Isogeometric Analysis, which uses B-Splines and NURBS as basis functions, is applied to evaluate its performance. The analyzed PDE is Poisson's Equation. The method starts with a coarse mesh which is refined to obtain each scale, considering every current scale mesh's element as a subdomain to the following scale. Local problems of each subdomain are solved independently, and the system is executed iteratively. Isogeometric analysis shows to have a better performance regarding approximation error and convergence in the iterative method that was derived here, which favorably influences computational cost.