Horizontal beamsize contribution due to radiation on bending magnets is calculated using theoretical results and recent improvements in mapclass (Mapclass2). In order to verify the code and validity of its approximations, a simple lattice with no geometrical nor chromatic aberrations, one dipole and a final drift has been used to compareMapclass2 calculations and Placet tracking results. CLIC 3TeV lattice is optimized including the radiation effects. Current results show that correction of chromatic aberrations impose constraints in radiation improvement.